t0fu

I've had this IBM T42 laptop for over 3 years now. It originally had 512MB RAM in total and had worked fine but it lagged when i played certain games. Due to the lag i decided to upgrade the RAM and add a 1GB RAM to it. It works fine and it makes my laptop run a lot faster but i notice that sometimes my laptop freezes completely for no reason what so ever. It freezes at random times, sometimes it freezes when I have MSN open only and other times it freezes when I'm on Mozilla Firefox and running Microsoft Word and/or MSN at the same time.

My laptop started freezing after i put in the new RAM. I'm not a computer expert and i don't know much as to what i can do or how to solve this problem. People I've talked to have said it could be a hardware problem and/or software problem but I'm not sure what it is. I know that my computer supports the RAM because my uncle helped me buy it (He works at IBM). I've asked him why it freezes sometimes though and he didn't know why either.

Does anyone know what seems to be the problem and/or what i can do?

If you need computer specs and RAM details i can post it up.