Hi,
I find the footprint of the Norton AV at the stack trace of three minidump. You had better upgrade Norton AV to latest patches. If it still crashes, reseat the memort module to another slot and make sure your PC is not overheated.
Mini012906-01.dmp BugCheck 10000050, {f00018f5, 0, f00018f5, 3}
Probably caused by : ntkrnlmp.exe ( nt!ObpCloseHandleTableEntry+3b ) <-- maybe caused by hardware but not sure ??
Mini020306-01.dmp BugCheck 24, {1902fe, efa646ec, efa643e8, 8057dc88}
Probably caused by : Ntfs.sys ( Ntfs!NtfsCommonCleanup+2271 ) <- Stack trace has footprint of Norton AV
Mini021706-01.dmp BugCheck 24, {1902fe, ef8f01dc, ef8efed8, 8057dc88}
Probably caused by : Ntfs.sys ( Ntfs!NtfsCommonCleanup+2271 ) <- Stack trace has footprint of Norton AV
Mini021906-01.dmp BugCheck 100000D1, {408b0c45, 2, 1, f79f583b}
Probably caused by : hardware ( mouhid!MouHid_ReadComplete+5 ) <-- hardware problem (ram, m/b, psu or overheat)
Mini022306-01.dmp BugCheck 1000008E, {c000001d, f0a49839, f07a2968, 0}
Probably caused by : SYMEVENT.SYS ( SYMEVENT+a839 ) <-- caused by hardware problem (ie ram or motherboard) or software error of Norton AV
Mini030206-01.dmp BugCheck 1000008E, {c0000005, bf80197a, efc90920, 0}
Probably caused by : win32k.sys ( win32k!HMAssignmentLock+26 ) <-- caused by hardware problem (ie faulty ram)