Crashes, freezes and the occasional bsod.

Hi everyone,
I've got a three year old toshiba laptop running win7 home premium 32bit which isn't particularly great, but it has served its purpose. Any way, Yesterday the laptop froze, upon start up it froze again before I was able to open any programs. I've restarted it possibly twenty times with several different results. Several freezes after thirty seconds, several froze before I'd entered my password, three bsod's which I didn't note, but I had noticed that "physical memory" was mentioned.
I know there isn't much to go on based on that, but I've not got any more information to go on. I've attempted to reinstall win7, but the computer freezes long before I can start the install process. Also, for some reason I don't have any restore points for when I try to system restore.

Any help you can provide would be fantastic, I need this back up and running asap.

Thanks in advance.

Thanks for the quick reply. The laptop won't actually stay freeze free for lo g enough to complete or even begin any of the tasks. I've just started the laptop a d startup repair has attempted to fix the issue, which it has failed at. I have the problem signatures if these help?
Problem signature 1: 6.1.7600.16385
Problem signature 2: the same as 1.
3: unknown
4: 404
5: autofailover
6: 1
7: norootcause

Hope these help.
Thanks.