New Build Problems

[JIMBOB73505]

I'm new at this so please bear with me. I have just finished building a new computer. Specs - ASUS p4b266 MB, 1.8A P4, 256 DDR SDRAM, MATROX G550 Video Card, etc. I have the system dual boot with Win98SE and WinXP. 98 works fine but I have some problems with XP. I am using the on-board sound card as was recommended in these forums. Initially I had a few minor problems with sound (not playing when XP starts and only playing sometimes when a program (Turbo Tax) loads. Have downloaded new sound drivers and this appears to have corrected the problem. Have also downloaded new video drivers for XP. System just doesn't seem to be running right with various minor problems such as XP will not always start on initial boot, etc. The biggest problem occurs when I use XP Media player. It has locked up several times and a short while ago I got a blue screen identifying the G550 as the cause for the system locking up. When I rebooted I got a message taht the system couldn't start beacuse the file "Windows root\system32\hal.dll" was missing or corrupt. Restarted in 98 and the file is in XP. I have now reloaded XP but don't want to try Media Player until I get some ideas on possible causes of problem(s). Any thoughts would be greatly appreciated.