stuck at splash screen after ram upgrade

Hope you can help as this makes no sense to me. I swapped out the ram on a dell dim2400 and now it wont go past the win xp splash screen even after i put the old memory back. All i did was unplug power open the case and swap the memory no poking around or anything. any ideas?

 

Try only one stick of new RAM to begin with - any luck?

 

Can you get into setup or into safe mode?

 

Thanks I think I resolved it. after about 30 min. I was able to get it to safe mode with command prompt where i was able to do a system restore but it didnt act the way it normally does when I run it. it did its shutdown thing like always but didnt come back on it just stayed dark. so I got out the old hand crank and turned it on manually clicked on "boot to other partition" in f8 and a screen came up where I could do a system test which said my cache had been deleted or disabled ( if someone could tell me what that is I may be able to remember what happened to it!) . so I booted from the xp disk and let it load all the drivers and such. Then after an what seemed like a year, the screen comes to life and says your computer has been succesfully restored to blah blah and booted right up no problem and runs great. now I'm even more confused. what was wrong with it exactly? and, what fixed it, exactly? any ideas? did I damage the flux capacitor somehow? all I did was upgrade the ram.

 

Next time you add memory to a Dell, enter the BIOS on reboot to register the changes.

There is n ormally a bios screen to tell you this before Windows starts.