Can't boot :C when OC'ing? Reset of BIOS and everything.

Hey,

I tried OC'ing for the first time yesterday.
And it went fine > 4.05gz with 9*450. [1.29v]
Then I tried 8.5*500[1.33v] and it worked. Then I went out, did some shopping and when I came back I couldn't load windows or the :C device where my OS is.
I did not touch anything while OC'ing (except FSB and multi), and I did reset my BIOS even, but still I couldn't lauch OS from :C. It found :C drive and I tried :C as both first and secound boot device, still no luck.
Well, now I've installed windows all over and it seems like it's working.
Does this have any connection or was it something else which caused my problem?

If an overclock is unstable, then it can crash and corrupt HD data especially whilst loading the OS. The only way out of it is to format/repair from what I know.

So if I make 1 unstable OC I can crash my comp?
Because I turned the OC back to default (333) and everything, but I was still unable to load

Well all it takes is one crash then bam corrupt, it might happen it might not, I have had a few crashes with a raid setup but it has survived (got an image of it anyway just incase).

That sucks,

If I use raid 1, does it crash both disks or just the first?

When the computer is loading device, will it count a 2 disk raid 1 set-up as one disk? So if it can't load the first, it won't be able to load the image disk?

Moreso, your corruption happens when the RAM is pushed too far. CPU overclock too far rarely causes corruption, at least in my case.
RAM pushed too far was always the source of my corruption. Luckily most of the time a chkdsk can fix the corrupted issues and make it bootable again.