and missing Start Menu listing sounds like that malware which is doing the rounds, "Windows Security" or similar.
Try the options offered by Carol in her post here;
Any error codes on that BSOD, (Blue Screen of Death), and any file names mentioned? They will be significant, especially if there is hardware failure pending.
I have a dell inspiron 1720 running vista, not to old, but it hasn't been touched in a while because of some problems. I'm not sure if it's a bad virus or if possibly the the hard drive is fried. When I boot it up, is asks me how I want it to start up. (Safe mode, normally, so on and so forth) it takes a minute, but finally it's at the homescreen. Here is where things get complicated, there are no files visible on the desktop, well only this random icon labeled cloud protection or something. I open the start menu, nothing but power down options. After about 2 minutes of being on, the computer crashes, blue screen of death, files are dumped, all that. Turn it on, and all that is repeated. I've tried various ways to restore the computer, including F8 on startups, and using command prompt rstrui.exe. F8 on brought up advanced option, none involving restore options. Rstrui.exe started to restore the computer back to a previous point in time, but it failed. And now there are no restore points to use. Does anyone have any suggestions or ideas to save this computer?