I have Avast installed on my Windows 7 computer and it is fully up-to-date. Today I ran a utility to defragment my hard drive and there were some files it did not adjust.
One of them is C:\Program Files\AVAST Software\Avast\setup\vps_defs_common-a66.vpx. This is a large file (170+MB) with lots of fragments (1400) and based on that which I have read, it is safe to delete this file. When I try to delete it, I get the error: You require permission from Administrators to make changes to this file. I then rebooted my computer into Safe Mode, logged in as the Administrator, but got the same error message.
But I would say the short answer is you can’t, it is protected by avasts Self Defence module, like files in the avast folder locations.
Not to mention if it is related the virus definitions, even if you were able to defragment it, that could corrupt it. Virus definitions are constantly being updated so there is going to be change (but 1400 seems excessive.
That said I don’t have that file in that folder, see attached image 1.
The main area for virus definitions is, C:\Program Files\AVAST Software\Avast\defs, see image 2
Mainly I would say, even if this file were to be able to defragment this file there is no guarantee it would reduce the size very much.
Note: I also have vps_defs_common-a66.vpx approx 170Mb (dated today) located in the C:\Program Files\AVAST Software\Avast\setup
That is with Avast Free Antivirus 21.9.2494 (build 21.9.6698.703).