PC question

I got a 1GB stick of ram today (1GB PC3200 3200 400Mhz DDR 400 Mhz 184PIN- what my pc requires).... inserted said stick into my pc, then proceeded to turn it on.

Had a message on startup saying that there was more memory added, and to press F1 to save changes. So I did. Pc then continued to load up.

However once it gets to the Starting up windows screen- just before where you chose which user is going to log on and enter password, it restarts. Gets to the same point again and just keeps restarting and loading up to the same screen again.

Though if on start up, I chose safe mode the computer starts up fine. Then on system properties it shows that the memory has been added.
But I can't get it to restart in normal mode- it just does what I previously said.


Then if I remove the stick of ram I can use the pc normally again.

Any ideas on how to sort this problem out would be appreciated..