Fri, Aug 05, 2022 5:01 pm
Running java from an Eclipse installation from the command line
For an introductory
class I am taking, I installed the
integrated development environment
on a Microsoft Windows 10 system. In addition to compiling and running
Java programs through the IDE, though, I wanted to compile Java programs using
the Java compiler, javac.exe, and run them using java.exe from Windows'
command-line interface (CLI). The installation process for Eclipse
installed the javac.exe and java.exe executables in a user directory with
a long directory path to those executables. Note: you should install the
Eclipse IDE from the account which you wish to use to compile and run
java programs. The location wasn't added to the
variable, so if you try to run the programs from a command prompt, you will
see the following, unless you specify the full path name where the executable
files are located.
'java' is not recognized as an internal or external command,
operable program or batch file.
'javac' is not recognized as an internal or external command,
operable program or batch file.
I didn't want to have to copy and paste the full path on the command line
or type it in every time I wanted to use the two executables from the
command line. To avoid that problem you can add the directory path to the
path environment variable through a
set path= command or create
another environment variable, e.g., JAVA_HOME that points to the directory
where the two files are located, though both methods apply only to a particular
command line instance. I.e., if you close a command prompt window where you've
set one of the variables to include the location where Eclipse installed
java.exe and javac.exe then open another command prompt window, you will have
to set the environment variable again in the new instance. An alternative
way to make a permanent path change from a command prompt interface is to use
setx command, though I would not recommend it, since if
your path variable already has a path that is more than 1,024 characters long,
setx can truncate the path to 1,024 characters, so that you not only don't
get the additional directory added to the path, but you may lose some of
the path setting you had prior to issuing the command. If you want to
make a permanent change, see responses to the
"Overcoming the 1024 character limit with setx"
posting at the superuser.com site.
[More Info ]
Mon, Jul 11, 2022 9:08 pm
Enabling Wake on LAN (WoL) on a Dell PC with a Realtek PCIe GBE NIC
Computers that support the
Wake-on-LAN (WoL or WOL)
standard can be awoken from a sleep state by sending a
" to their network card from another system. For an
packet is an Ethernet
that is sent to all systems on the
local area network
. The packet contains 6 bytes of the
FF followed by 16 repetitions of the 48-bit
media access control
address of the system to be awakened from a sleep state.
I tried unsuccessfully on Friday to remotely "wake" a Dell PC from another PC
by connecting to the other PC on the same LAN and then sending a
to the sleeping computer using the Wake-on-LAN
—I no longer see
a download link for the free software for Windows systems on the developer's
website, but you can download it from a snapshot of the site taken by the
December 19, 2007 at
where you can also find the utility
that will allow you to obtain the MAC address for a
interface card (NIC)
on another computer, or you can download
another free program for Windows systems created by Nir Sofer. After the user
powered on her Dell computer this morning and left the office, I connected to
her system remotely to verify that the system is configured to respond to a
magic packet to wake it when it is sleeping.
[ More Info ]
Fri, Jun 24, 2022 10:22 pm
Raising a number to a power in Microsoft Excel
There are two ways to use exponentiation, i.e., to raise a number to a power in the Microsoft Excel
spreadsheet program. You can use the POWER(number, exponent)
e.g., to raise 2 to the power 3, you could put
a cell which would yield the value 8. Or you can use the exponent operator, the
(shift-6 on a Windows keyboard).
E.g., to calculate 2 raised to the power 3 you could put
in a cell which produces the value 8.
Thu, Jun 23, 2022 9:46 pm
Maximum memory for an HP 3047h Motherboard
A family member said a Windows 10 system she is using for gaming is running
slowly and inquired about adding additional memory to the system. I didn't
know the model of the motherboard in the system nor the maximum amount of
memory it could accomodate. Rather than opening up the desktop system, I
checked on the manufacturer and model of the motherboard from a command-line
interface (CLI) with a
Windows Management Instrumentation Command-line (WMIC) command and
found it was a Hewlett-Packard (HP) 3047h motherboard.
Microsoft Windows [Version 10.0.19043.1766]
(c) Microsoft Corporation. All rights reserved.
C:\Users\Colleen>wmic baseboard get product,manufacturer,model,serialnumber,version
Manufacturer Model Product SerialNumber Version
Hewlett-Packard 3047h MXL11925F3
I also saw 3047h listed as the "baseboard product" ("baseboard" is
another name used for
"motherboard") when I
System Information in the Windows
"Type here to search" field and selcted that application.
[ More Info ]
Wed, Jun 22, 2022 9:49 pm
Excluding a file or directory from monitoring and scanning by Acronis Cyber Protect Home
Because Acronis® Cyber Protect Home Office, which is backup, cloning,
and antivirus software for Windows and macOS systems, was prompting a user
as to whether Java should be allowed to run on a Microsoft Windows system on
which it was needed, I wanted to exclude the Java.exe program from monitoring.
The process to exclude a program from monitoring and scanning by that
application is as follows:
- Start Acronis Cyber Protect Home Office. When prompted "Do you want to allow
this app to make changes to your device?" to allow
CyberProtectHomeOfficeLauncher.exe by the verified publisher Acronis
International GmbH to run, choose "Yes."
- Select Protection, if it is not already displayed.
- Click on Protection Exclusions then click on Add exclusion
and choose either Add file or Add folder depending on
whether you wish to exclude either an individual file or an entire directory
from being scanned and possibly flagged.
- When you select an option, e.g., Add file, you can browse to the
relevant locaton and select what you wish to exclude from monitoring
and scanning activities.
- Click on Save to have the application keep the changes you've
Tue, Apr 05, 2022 6:05 pm
Let's Encrypt Problem binding to port 80: Could not bind to IPv4 or IPv6
A couple of users notified me that they were receiving warning messages
regarding the security certificate on their email server when they were
checking email with
. I checked the expiration date on the security
certificate for the email server with the
openssl s_client -connect pop3.moonpoint.com:995
system is using
software program providing users with the ability to download their email).
Dovecot listens on
port 995 for
email connections for downloading email.
I could see the certificae was expired and I issued the
command when I saw the "OK Dovecot ready" prompt.
The email security certificate on the system is provided by
so I then tried renewing the certificate from the root account with the
command, but was unsuccessful.
I found the solution was to stop the
Apache web server
software running on the system, thanks to a post by JuergenAuer at
Renewing certificate getting error: Problem binding to port 80: Could not bind
to IPv4 or IPv6
. After I stopped the web server software, I was able to
reissue the letsencrypt command to renew the certificate without the
"Problem binding to port 80" error message. I then restarted the Apache web
server software and Dovecot.
[ More Info ]
Tue, Mar 29, 2022 9:42 pm
Close Microsoft News and Interests Popup
On a Microsoft Windows 10 system, unless the
News and Interests
feature has been disabled, you will see an area at the bottom right of the
screen in the notifications area, aka status area, of the
information about the weather, such as the local temperature where you live.
You can click on that area to view the titles of news articles deemed of
interest to you. When you click on it, you will see something similar to
what is displayed in the image below.
If you click outside of the area, the area that pops up with the news articles
will normally go away, but sometimes it will remain and won't go away if you
click elswhere, hit Escape, click on the refresh icon in the area,
etc. There is an option to disable the News and Interests display, which you
can get to by right-clicking on the area where the temperature is displayed.
But if you do that when the popup display for News and Interests is stuck
on the screen then you can't see the options area to disable it because it is
behind the area where the News and Interests appear and is thus inaccessible.
In such cases, I've found that changing the display settings and then reverting
the settings to what they were resolves the problem. You can get rid of the
News and Windows popup display by the following steps:
You can hit the Windows
key (the one with the Windows symbol on it, which may be on the left side
of your keyboard between the Ctrl and Alt keys, to display
the desktop. Or, alternatively, you could manually
minimize all open windows.
Right-click on an open area somewhere on the desktop and select Display
Settings. If the Display Settings window isn't fully visible when you do
so, drag that window into a position where you can see the settings.
Change the display resolution.
When asked whether you wish to keep the new resolution or revert to the prior
resolution, choose Revert.
The News and Interests display should then disappear. You should be
able to click on it again, though, if you want to see the latest news
headlines, but have it go away when you click elsewhere.
[ More Info ]
Fri, Feb 04, 2022 3:27 pm
Evernote - Clipper has encountered an error
Recently, when I've tried to save a webpage to
browser, I frequently see the message "Clipper has encountered an error"
with "Unknown error occurred. UNK."
I have been able to save the page by disabling and then re-enabling
the Evernote extension in the browser. In the Brave Browser, you can
do so by closing the error message window, then clicking on the icon of
3 short horizontal bars at the upper, left-hand side of the Brave window
which will display a menu of options. Select "extensions" and then click on
the red slider button at the bottom, right-hand side of the Evernote Web
Clipper extension to turn it off (it will go from red to gray).
Then click on it again to re-enable the extension. You can then close
the Brave extensions tab (brave://extensions). You will then need to
refresh the page. After I've disabled and re-enabled the extension when
I've seen the error message, I've then been able to click on the icon for
Evernote near the browser's address bar and save webpages to Evernote.
Sat, Jan 22, 2022 10:37 pm
AMD FX-6350 Six-Core Processor and Windows 11
When I went to Settings then Update & Security on a computer running
Microsoft Windows 10 to update it to Windows 11, I saw the message
"This PC doesn't currently meet the minimum system requirements
to run Windows 11" and "Get the details and see if there are
things you can do in the PC Health Check app." So I clicked on the "
Get PC Health Check
" link and downloaded and installed
the application. When I ran the program, it reported "This
PC doesn't currently meet Windows 11 system requirements" and
provided details as to why that assessment was made. The system
has adequate memory, disk space, and a 3.9 GHz processor (the
minimum processor speed required is 1 GHz) with 3 cores (2 or more
are required), but there was a warning that "This PC must support
Secure Boot" and "TPM 2.0 must be supported and enabled on this PC."
Unified Extensible Firmware Interface (UEFI)
specification. The system is configured for UEFI
booting but, even if it wasn't, the October 11, 2021 article How
to Install Windows 11 on Legacy BIOS without Secure Boot or TPM 2.0
by Parth Sawhney provides a workaround for systems booting from Basic Input/Output System
, which UEFI replaced.
But the indication that the AMD FX™-6350 Six-Core Processor was
not supported seemed a showstopper. I also checked the June 29, 2021
List of Intel and AMD Processors NOT Supported by Windows 11 by
Shivam Malani and found the FX-6350 processor is also listed there. The
author of that article notes “there’s an endless list of processors
that Windows 11 doesn’t support. Even systems capable of flawlessly running
high-end games aren’t eligible for Windows 11 due to the limited hardware
support” and states that if a system is more than four years old
that it is very less likely to be among systems that can be upgraded to
Windows 11. A list of
Devices (AMD) processors supported in Windows 11 can be found
in the December 2, 2021 article
Windows 11 supported AMD processors on the
Microsoft Docs website.
You can obtain brief details on a system's processor through
Windows Management Instrumentation Command-line (WMIC)
at a command prompt inteface.
C:\>wmic cpu list brief /format:list
Caption=AMD64 Family 21 Model 2 Stepping 0
Name=AMD FX(tm)-6350 Six-Core Processor
You can check the full details on a processor from a
interface (CLI) with
wmic cpu list /format:list.
Mon, Jan 17, 2022 10:09 pm
Western Digital My Book disk drive P/N WDBBGB0080HBK-NA Adapter
I found a Western Digital 8 TB My Book external USB disk drive with part number
WDBBGB0080HBK-NA in a box with a number of other disk drives, but the box
did not contain the power adapter for that drive. The back of the drive has
"12V" next to the place where the power adapter connects to the drive but
no indication of the amps needed. You can find a listing of the specs for
power adapters needed for various disk drives at Western Digital's
Power Adapters for WD Products
webpage. That page shows that
the My Book drives with the following part numbers use AC adapters that
are 12 volts, 1.5 amps, and 18 watts.
Note: you can find an explanation of the format Western Digital uses for
their model numbers in the PDF file downloadable from Western Digital at
Model Numbers - Branded Products or
here. For older
drives, Western Digital also provides a
Retired Model and Order Number Formats for WD Products document that is also
In this case, the "0080H" indicates the drive is a 3.5" drive with a
capacity of 8TB.
I didn't have a power adapter from another Western Digital drive handy that
met the required specifications for volts, amps, and watts. I could order
a needed adapter online—the WD 18-watt power adapter is model number
while the 36-watt version is model
WDPS039RNN—from Amazon and receive the adapter in just a few days, but
I needed to check on whether that particular drive held a needed backup
immediately. I had a Seagate Backup Plus 5 TB USB 3.0 Desktop Drive available
with an ADS-18E-12N power adapter which lists an output of 12V and 1.5A on the
adapter, so I figured I could use that drive, since though that adapter
doesn't list the wattage, the formula to calculate watts if the amperage
and voltage are known is amps x volts = watts and 12 x 1.5 = 18
(Obtain Watts from Amps and
Volts provides an online converter). So I was able to use the Shenzhen
Honor Electronic Co.
adapter from the Seagate drive on the Western Digital drive. Unfortunately,
though it held a backup for the system for which I needed to recover files,
that backup did not contain the needed files.
Specs of the WD Essential Power Adapter
By Dan Ketchum
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