First - I'm a n00b. I'm happy to learn anything about diagnosing a bad comp that you'd like to teach.
System - Windows XP Pro, all available Windows updates installed (minus MS .NET framework 1.0 SP 3 - fails to install on comp). No malware (using products from GeeksToGo/Malware, HJT log clean, etc.). No hardware recently installed. Hard drive has ~10 gigs left.
Crashes - Crashes are often spontaneous. These are sometimes caused by unplugging ethernet cable from card. Has also crashed after pressing "Restart," but does NOT crash during reboot. Random problems have occurred - Norton Antivirus and Ad-Aware had internal errors during the same session, both of which resolved after reboot.
Warning Message in Event Viewer (recurrent, edited for privacy):
Your computer has automatically configured the IP address for the Network Card with network address "xxxxxxxxxxxx". The IP address being used is "xxx.xxx.xx.xxx".
(In event viewer format - ex: 1000007e = 0x0000007E, c0000005 = 0xc0000005, 0000000a = 0000000a, etc.).
These errors have occurred on separate crashes or together. The errors often change from crash to crash.
Error code 1000007e, parameter1 c0000005, parameter2 804e280e, parameter3 f7a3ac24, parameter4 f7a3a924.
Error code 1000008e, parameter1 c0000005, parameter2 804e2801, parameter3 f778ebf8, parameter4 00000000.
Error code 0000000a, parameter1 8cae1b1c, parameter2 00000002, parameter3 00000001, parameter4 804ee2a0.
Error code 0000000a, parameter1 8cc4b084, parameter2 00000002, parameter3 00000001, parameter4 804e4eb0.
Error code 0000000a, parameter1 8800000c, parameter2 00000002, parameter3 00000000, parameter4 804df6ac.
Error code 000000c2, parameter1 00000043, parameter2 80000000, parameter3 00000000, parameter4 00000000.
Error code 00000050, parameter1 8c7e2300, parameter2 00000000, parameter3 80556d22, parameter4 00000000.
There are more errors I could dig up, but these should hopefully provide a starting point for a general diagnosis. I'm eager to find out what's wrong before the problem gets worse.
Thanks so much for your assistance!