4GB ram vs. 2GB ram in vista ultimate

[SwaggMan]

hello. having a problem with this system we just put together.

asus mobo p5n-e sli
250 gb hd with mirror raid
radion hd 2600 pro graphics card
vista ultimate 64 bit
4 gb ram

installing vista with the 4 gb ram, system restarts during the final loading screen (green scrolly bar at the bottom)

took one 2 gb stick out and was finally able to finish installation. put the 2 gb stick back in (so 4 gb now) and it restarts as windows is loading again.

replaced one of the 2 gb sticks with another, got 1 successful logon, then when i restarted, it went back to restarting during startup.

plz let me know what i can do. i will keep messing with differant configs till then.

[cking]

[SwaggMan]

no, it would start up fine with both single sticks of 2 gb ram. only when putting te 2 together ( =4gb ram) is when it would restart. i got 1 successful log in with 4 gb of ram, then a restart loop. switched back to only 2 gb (1 stick) it would start .switched it again back to 4 gb (2 sticks) it would restart continueously. the guy settled with 3 gb (1-2gb and 1-1gb) that seemed to work fine and he wanted his machine : /