system freezing during XP bootup

[xeonzx86]

i have a dual boot system (xp and 98se)..initially when system used to start in XP, then after half an hour screen used to freeze(without runnin any prog). now it has stopped booting in xp.....when i tried to boot in safe mode....it gets stuck at "mup.sys".

---->another problem which i noticed from last few weeks was that whenever i play any game like DOOM3.or NFS underground it used to show weird artifacts(strange colours).......i even updated my drivers(nvidia) to 66.93 but no diff.

so wat could be the prob?...do i have to reinstall XP(system seems to run fine in 98!!)
i hope graphics is not fuked!!!



My system---
-Athlon 2400
-512DDR(pc2100)
-A7N8x-x
-Geforce4 MX440
-40GB samsung
-160GB seagate
WINXP(prof) sp2(slipstreamed)

 

[xeonzx86]

ok.another new development...now system is freezin in 98 also.i have 98 installed on 80Gb hdd....and winXP on 160Gb hdd

 

[montag451]

try new vga card

 

[montag451]

or ram
or psu

 

[xeonzx86]

problem is i don't have any spare hardware with me...............

EDIT
just now i switched that machine on...and now it booted perfectly in XP........