Toshiba Satellite p25-507 will start up to windows then freeze up

I have a Toshiba Satellite p25-507 I had the original hard drive go out on me so I doubled it up and got the western digital 120 gb I then installed windows vista ultimate. everything was working fine always was on auto update so it got all the updates I belive. Then months later it began to freeze on me. The mouse wouldnt move the cursor, no buttons worked. I had to hold the power button down to shut it down. I would restart in safe mode then restart again. Things would be ok for a bit then again, and again it happened freezing faster or sooner than before. Now it freezes soon after it is booted up and running.

The power source box located in the middle of the power cord was stepped on and broke where the cord plugs into the box, it is loose but still plugs in and seems to work fine. The battery is getting a good charge. So the power source wouldnt be the problem would it?

I have used this laptop alot over the last 6 years so its had maybe 50% more usage than some others of the same age. Maybe something went out.

I purchased a hard drive enclosure to bring up the hard drive on another pc and all my files, pictures and so forth can be reached and saved. I was thinking of formating the hard drive and re-installing vista or XP. If the problem could be in the hard drives files. I have no idea what to do.