Windows XP – System Randomly Crashing

Computer is running windows XP.

seems to be crashing randomly, no pattern in its timing or activity to cause it.

What could be causing this/how do I diagnose this?

Event log shows

>Event Type:    Error
>Event Source:  System Error
>Event Category:    (102)
>Event ID:  1003
>Date:      22/02/2011
>Time:      7:10:05 p.m.
>User:      N/A
>Computer:  YOUR-8ABC512DA0
>Description:
>Error code 1000008e, parameter1 c0000005, parameter2 bf801b50, parameter3 ee118c44, >parameter4 00000000.
>
>For more information, see Help and Support Center at >http://go.microsoft.com/fwlink/events.asp.
>Data:
>0000: 53 79 73 74 65 6d 20 45   System E
>0008: 72 72 6f 72 20 20 45 72   rror  Er
>0010: 72 6f 72 20 63 6f 64 65   ror code
>0018: 20 31 30 30 30 30 30 38    1000008
>0020: 65 20 20 50 61 72 61 6d   e  Param
>0028: 65 74 65 72 73 20 63 30   eters c0
>0030: 30 30 30 30 30 35 2c 20   000005, 
>0038: 62 66 38 30 31 62 35 30   bf801b50
>0040: 2c 20 65 65 31 31 38 63   , ee118c
>0048: 34 34 2c 20 30 30 30 30   44, 0000
>0050: 30 30 30 30               0000