It could be normal for some 2000 era and older machines. To fix those we replace the machine. If it's just the wrong RAM we head to crucial.com
Bob
When I tried putting 2gb of ram in my desktop, it boots up then randomly shuts off about 15 seconds in. I then took one ram slot out making it only 1 gb, and it worked perfectly. Well kinda... I'm running windows vista so with only 1gb it is EXTREMELY slow!!! If you know how to fix this, I will be forever grateful as I need this computer for my schoolwork

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic