Windows (files) gets corrupt over time and there is nothing you can really do about it except reload it on a blank (reformatted) hard drive but then you have to reload all your programs too and that could take time. Win7 is becoming mature but doesn't support a lot of older programs yet if ever (like Kitco quotes). Leave it to me to get the blue screen of death on Win7 when I was loading some drivers for a old sound card. XP drive is still primary and Win7 drive backup and storage.
Always backup you important files to flash drive, DVD, CD, another drive, web, whatever.
Playing some miners to take profits. Don't know how much of a pull back is expected but one is due in the short term.
I have up to date Norton Ghost files on a hard disk I take away to my bedroom

I probably will stay with XP in this lifetime
I spread the word of my trouble on the Norton Forum and a Senior NIS developer asked me to be allowed to help
They don't seem to like customers going to Mc Afee

I have used NIS ( 2 troyans in C system recovery) Adaware ( Troyan and virus in D system recovery ) 3 Registry scanners turning up 20 problems with Norton but set to ignore and I cannot find how to unignore them . Right now running Spybot search and Destroy after I finished with CCleaner . Running process explorer telling me the last reboot still holds. Will have to find out about Process Monitor why Norton db files are using 2 gigabyte RAM
I made a bundle on miners and lost more on physical in Euro
Sold all Drooy and HMY and now am evaluating when to reduce uncle Jim Tanzanian
which is at 80% Slow stoch month and week and dayly
Consider buying Lake Shore or Kirkland
Kirland has very good technical pic but reading their site they are guys standing around a hole in the ground . Hope old Jinshan comes down
So I got 3 kind of miners
TNX.to ready to sell
Yamana, GBG,MFL,NGD nice
K.to;NG; Oceana in limbo
12.5% cash