SadisticalActs

I recently purchased a brand new Sata 320gb HD. It has been working fine, no issues and have had it for about a month. I installed the windows 7 beta to test, and it wasnt stable so I reinstalled vista back on. I was using vista fine like usual. Then I left PC on and went to bed and woke up and the vista desktop was all lagging and messed up. So i restarted pc, and when it came back on it said cant find boot device. I went to reinstall Vista again after some repair techniques. and When i came to harddrive part, it said make sure harddrive something is enabled. and wouldnt let me install on HD. i tried a windows XP instalation and it told me i couldnt use harddrive. So I stuck my old HD in an IDE one that is about to go out. and Loaded Vista on it, and plugged sata one back in, and nothing shows up, it shows up under disk management and it says its unreadable. The harddrive was not defective, and had no issues with it untill now. Is there something I can run to fix, or did windows 7 do like some setting to it.

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Custom

Windows Vista Ultimate 32bit
Intel Core 2 duo 2.6ghz
2gb ddr2
500b harddrive
580w PSU
Geforce 9800+GTX 512mb