Windows reboots after RAM install

[ZealEmpire]

Well I recently upgraded the memory in my pc from 512 to 1gig.  It is 2700 series in my dell.  Everything seemed to be fine and I check the system properties to make sure it registered as a gig which it did.  So I reboot the computer again and when I get to windows programs begin to crash one of which is the explorer.  After explorer crashes my computer just reboots itself only to do the same thing again and again.  Can someone please give me a hand with this problem... :-/

[ZealEmpire]

Now the computer gets a window shortly after i log into windows that says "The System has recovered from a serious error"...then I hit the do not send button and the computer shuts down....

[ZealEmpire]

Ok its gotton to the point that I cant even get into windows...how can I get to the dos prompt if the computer has no floppy drive...I am going to have to format the computer an install windows again...please help guys this is getting awful  

[GX1_Man]

Undo what you have done and see if it still works as before. We need only one variable at a time.

[Mac]

Well I recently upgraded the memory in my pc from 512 to 1gig.  It is 2700 series in my dell.  Everything seemed to be fine and I check the system properties to make sure it registered as a gig which it did.  So I reboot the computer again and when I get to windows programs begin to crash one of which is the explorer.  After explorer crashes my computer just reboots itself only to do the same thing again and again.  Can someone please give me a hand with this problem... :-/

What color ar the slots? If you have two different colors and have only two modules use two slots of the same color.