XP Pro Stop Errors

dual OS,XP Pro and ME..ME boots and run fine,when booting to XP I get a BLUE SCREEN with a stop error that reads as follows= STOP: c0000221 Unknown Hard Error\SystemRoot\System32\ntdll.dll.I have tried all the available resorces,sys rescovery,restor,debug and so on,as a last ditch attempt I have tried fomatting C: reinstall XP using Full/Clean install option and get the same error,did it again,same results.the System ia SOYO VIA K7 KT133A mobo,900 MHz AMD Athlon,512 Meg SDRAM PC133,nvidia GeForce2 GTS 32meg and so on.Got any help,ideas or cures please send it..THANKS DR