I have got some malware or virus I scanned with AVG it didn't worked the problem is on a machine with Win Xp +sp2 an

Tools-->Folder Options--->Hidden Files and folders -->Show hidden files

when ever I click on this option and press apply button and go in some other folder
then again opening
Tools-->Folder Options--->Hidden Files and folders -->Show hidden files
this option is unchecked .
I repeatedly did it for same folder many times but this problem is still there i am not able to keep this option permanently.
This problem keeps repeating on every drive and all folders .

After posting here I was searching I have got a solution to my problem this problem is caused by a virus named d.com and amvo

If your system is infected by this virus you can’t see hidden files and folders , even after applying the settings to show hidden folders. This setting is reverted back to Don’t show hidden files and folders by the virus.

This happens because virus protects the two hidden ,system files called d.com and autorun,inf which are created by amvo.exe and amvo0.dll , amvo1.dll which resides in system32 folder on the OS drive (hard disk partition on which windows operating system is installed).

this problem can be solved by using a script given here
http://www.mygeekside.com/downloads/...rus_usb_en.vbs

or if you want to manually try then here is the solution
http://www.troublefixers.com/how-to-...ti-virus-tool/
http://www.troublefixers.com/hidden-...e-not-visible/

Interestingly enough, malware often prevents anything that could cause it's demise. This also includes updates for security programs. It's caused 'survival'; and even computer malware does whatever it needs to survive!