Issue with new computer

Hi,
I have a new custom built PC based on a ASUS 5K MB, Dual Core 6750 processor, an XFX 8800 GT 512Mb graphic board, 4Gb RAM a 675W PS and running XP SP2.
I have loaded both Fs9 (+update) and FSX, SP1 and SP2 without any add ons but keep having CTD's on both.
I want to troubleshoot this problem systematically but can't help thinking the problem is with the PC not the programs.
Could anyone offer any advice on how I could approach getting a stable base installation of both programs?
I am not that tech savvy, but can follow instructions....
All ideas, help much appreciated.
Best
Speedbird217
I have a new custom built PC based on a ASUS 5K MB, Dual Core 6750 processor, an XFX 8800 GT 512Mb graphic board, 4Gb RAM a 675W PS and running XP SP2.
I have loaded both Fs9 (+update) and FSX, SP1 and SP2 without any add ons but keep having CTD's on both.
I want to troubleshoot this problem systematically but can't help thinking the problem is with the PC not the programs.
Could anyone offer any advice on how I could approach getting a stable base installation of both programs?
I am not that tech savvy, but can follow instructions....
All ideas, help much appreciated.
Best
Speedbird217