Book Collector database disappeared

I use the book database software to manage my book collection. I hadn't updated the database for several months, but I had purchased some books recently and wanted to add those books to the database. When I opened the Book Collector program (version 16.4.3), it automatically opened the last book database I had open, which was one that I use to track books my wife and I have purchased as gifts for a friend who also enjoys reading, so I don't buy the same ones again in the future. But when I tried to find the database in which I store information for my own books, I couldn't find it. When I clicked on File and selected Open Database in the program and navigated to a folder where I thought that database was stored, the program didn't show the database at that location. When I navigated to that directory with the Windows File Explorer, I didn't see any files with a .bkc extension, which is the filename extension used by the Book Collector database program. also provides comic, game, movie, and music database programs. The file extensions for the various databases are listed below: file extensions for Windows
Music Collector:.muc
Movie Collector:.mvc
Book Collector:.bkc
Comic Collector:.cmc
Game Collector:.gmc file extensions for Mac
Music Collector:.mucp
Movie Collector:.mvcp
Book Collector:.bkcp
Comic Collector:.cmcp

In the directory where I expected to find the database file, I saw a file with the exension .bkctmp, which had a date and timestamp that I thought would correspond with the time I last edited the file and the file size seemed consistent with what I would expect for the database, since it was one I created just for books purchased in 2017. The file was Jim_2017.bkctmp.

C:\>dir C:\Users\Public\Documents\bookcollector
 Volume in drive C has no label.
 Volume Serial Number is 9420-A68C

 Directory of C:\Users\Public\Documents\bookcollector

05/21/2017  12:37 PM    <DIR>          .
05/21/2017  12:37 PM    <DIR>          ..
12/17/2016  08:09 PM           252,399 bkc6AC2.tmp
01/17/2017  09:54 PM           568,597 bkc766C.tmp
10/07/2016  05:22 PM           500,557 bookcollector_info.pdf
12/24/2016  12:29 PM                 0 capphrases.txt
12/26/2016  12:06 PM               428 details4columns.xml
12/26/2016  12:06 PM               181 details4group.xml
12/26/2016  12:06 PM               255 details4sort.xml
12/26/2016  12:06 PM               608 filters.xml
12/24/2016  12:29 PM            20,144 George.bkc
05/21/2017  11:28 AM               144 George.bkclck
12/26/2016  12:06 PM               462 itemcolumns.xml
12/26/2016  12:06 PM               163 itemgroup.xml
12/26/2016  12:06 PM               274 itemsort.xml
01/07/2017  06:15 PM           568,597 Jim_2017.bkctmp
12/24/2016  12:29 PM                 0 sorttitle.txt
              15 File(s)      1,912,809 bytes
               2 Dir(s)  71,762,505,728 bytes free


I renamed the file to Jim_2017.bkc and I was then able to open the file in the Book Collector program and see the books I had in the database.

I had also seen two files with the .tmp extension that had later time stamps than the .bkctmp one, so I tried renaming them to .bkc files also. After I changed the file extension from .tmp to .bkc, I was able to open both files. Perhaps the .bkc file disappeared when the system crashed or rebooted during an update to the database, leaving the temporary files. Thankfully, just renaming them allowed me to recover the list of books I had stored in the Book Collector database. I found that the .tmp file with the timestamp close to that of the .bkctmp file contained the same number of books as the .bkctmp file when I was able to open both of them after changing the extension on the files to .bkc. I kept the file I had renamed from .tmp to .bkc, since it had the later timestamp. So, if you see a message like "File xxxxxxx.bkc not found" when opening Book Collector, look for a .bkctmp file of the same name in the directory where you store your book database and change the extension on the filename from .bkctmp to .bkc.


  1. I do not see my data any more.