Find Windows' log of frequently used programs

Helpline Q&A Directory

Is there anywhere that Windows records the frequency with which programs on your PC are used? If so, where can I find it?

Yes there is. It is called optlog.txt and it is found in the Windows Applog folder. Optlog.txt is created by Windows for use by Disk Defragmenter. It can optimise the system by placing the most frequently used programs together where they can be accessed most rapidly. However, the file also provides an interesting insight into how your system is used. (Note: the Applog folder is hidden, so you must get Explorer to display hidden files before you can see it.)

Other files in this folder contain more detailed information about disk accesses performed by each program, including other files that are accessed, so that these can be placed near the programs that are used to open them. These files can also be interesting to look at (open them in Notepad or Wordpad) but they can waste disk space. For example, we found a 6MB file named after our virus scanner, which contained a log of all the files it had scanned.

If you want to reclaim disk space you can delete the Applog folder and its contents at any time. The contents will be lost, but it probably doesn't make much difference to performance if the defragmenter doesn't have this information available.

If you delete the folder, Windows will create a new one and start logging system usage again. The program Taskmon creates the log, which is one of the programs launched automatically by Windows at startup.

The only way to prevent usage logging from occurring - as far as we can tell - is to disable the launch of Taskmon using the startup page of the System Configuration Utility Msconfig.