Windows 7 strange large files and missing capacity

Question

i need your help. In

 C:\Users\<username>\AppData\Local\VirtualStore\Windows\System32 

i found this

file __rar_01.006 

and it's size is 1,7GB!!! can i delete it?

and more: if i trying to check size of

C:\Windows, 

then it shows 18GB, but if i enter in this directory, using ctrl+A and check volume, then it shows 15GB. Where Windows 7 eat 3GB? (hidden directories are shown)

Answer 1

The folder you are looking at is where Windows stores files in order to protect itself from bad users and bad programs and enforce the kind of user segregation and security that has been the birthright of every other multi-user operating system.

What happens is that when a user or program tries to write to a bunch of protected system directories (like Windows, or Program Files or even C:\) Windows itself will catch that file write and will instead put the file in this VirtualStore directory so that it is not seen by other users of the computer and therefore this file also cannot compromise filesystem or even system security.

If you really want to delete that file then chances are you need to actually go into your C:\Windows\System32 directory, sort files by size, and delete the file from there.

If you can't find the file there then yes, deleting it from the VirtualStore folder shouldn't cause a problem. The filename suggests it is a part of a multipart RAR archive, just delete it if you don't know what or where the other parts are.

Answer 2

So far as I know Microsoft does not use .rar files in any way as part of their OS. So this .rar.### file is not a critical OS piece and can be deleted. I'd wonder where it came from though. Rar are used by many file-sharing systems because they produce decently high compression rates and can be easily split, like this one was.

The file sizes have to do with virtual directories, which Windows Vista/7 make extensive use of to minimize file duplication and maximize space efficiency.