Corrupt admin permissions?

Hi all
I had a strange thing happen yesterday... but then, isn't that the story of our lives when it comes to computers? :D Anyway, a friend's computer just decided that it wanted to corrupt it's system file - no reason, it just blue-screened last week and when she restarted, she got the "file is corrupt or missing" message.

So, I replaced the system file from the windows\repair folder, and the system was go again. However, it was running VERY slowly, so I decided to do a repair install. This went fine, with one notable exception: usually, I have to re-activate Windows after a repair install - this time, it didn't ask to do so. At first, I was pleased - it meant I wasn't going to have to phone MS and get a manual activation (this PC has had it's share of probs in the last 12 months, and this would have made activation number 7!). However, I just happened to be poking about with deleting some unnecessary shortcuts from the Start menu, and got a message "access denied". Weird. "Fine", I thought, "I'll just do it manually". So I went into the admin user on C: and tried to delete the offending shortcut "manually" - only to get the same message and now the shortcut has lost it's pic and windows reckons it's not a valid shortcut! Thinking that perhaps the main user (Rae) was glitchy and causing a prob, a made a new user, logged off, logged on as the new user, deleted Rae (keeping files) and restarted - same problem.

I've spent ages farting about with this machine, and am at the point of just formatting the drive and reloading everything from scratch. This is not the first time that this PC has corrupted it's system file, but it is the first time that I've not been able to do a quick recovery. I've replaced ALL the components in the machine (so it's actually a new machine now!), so am picking that it is probably a faulty UPS that it's plugged into. Surely I couldn't be "unlucky" enough to have a whole new set of new components fault in the same way as the old components? :eek: :confused:

Anyway, all thoughts and comments appreciated.

Cheers
Peter

What were the circumstances leading up to this? Power outage, moved system, etc.

Run a diagnostic on the hard drive.

Nothing - it just blue-screened out of nowhere. I've done a full HDD test using TuffTest, then a low-level format - HDD had no probs. It just appeared that the HDD decided to allow the system to get corrupted: hence, my thinking that it could be a fault on the UPS. Another thought is that a USB device attached to the system periodically "glitches" it - I've seen that on some of the photo printers before, so perhaps my friends Epson photo printer is sending a "spike" p the USB?

Anyway, in the interim, I'd like to know how to fix this permissions glitch before I have to do a reformat. I've cloned the drive from an SATA to an ATA using Disc Wizard, so I'm no working off the original HDD...

Take ownership of the files and reassign permissions.
I'd format though - if you have had so many problems in 12 months it is the obvious thing to do.

Thanks - how would I go about doing that? I've already done the reformat, but I'd like to know for future reference how one goes about taking ownership of the files and reassigning the permissions.
Thanks