My Gateway computer, Pent II 350 Mhz is acting strangely. When booting, it looks ready for me to proceed -- but then the mouse is frozen and when I move the mouse the screen goes black and goes to Restart. It takes 2 or 3 tries to succeed. Sometimes it does this when working in email or on the web.

I bought it in 1998. In 2001 the computer crashed and a new hard drive was installed.

Any ideas?