1. Event Logs?
2. Blue Screen Error Messages?
3. Service Pack and hotfix levels?
4. What are the roles of this server?

these are the errors i found in the event log
 
Event Type: Information
Event Source: Save Dump
Event Category: None
Event ID: 1001
Date: 4/4/2003
Time: 11:20:42 AM
User: N/A
Computer: mars
Description:
The computer has rebooted from a bugcheck. The bugcheck was: 0x0000007f (0x00000008, 0x00000000, 0x00000000, 0x00000000). Microsoft Windows 2000 [v15.2195]. A dump was saved in: C:\WINNT\MEMORY.DMP.
 
Event Type: Error
Event Source: Service Control Manager
Event Category: None
Event ID: 7024
Date: 4/4/2003
Time: 3:25:22 PM
User: N/A
Computer: mars
Description:
The Routing and Remote Access service terminated with service-specific error 711.
 
Event Type: Error
Event Source: EventLog
Event Category: None
Event ID: 6008
Date: 4/4/2003
Time: 3:24:30 PM
User: N/A
Computer: mars
Description:
The previous system shutdown at 3:20:31 PM on 4/4/2003 was unexpected.
Data:
0000: d3 07 04 00 05 00 04 00 Ó.......
0008: 0f 00 14 00 1f 00 c5 01 ......Å.
0010: d3 07 04 00 05 00 04 00 Ó.......
0018: 07 00 14 00 1f 00 c5 01 ......Å.

Well I can only think of a couple of things barring I dont know what version of windows nor its service pack levels
 
1. Have you installed the High Security policy? .... this IIRC sets several services to disabled. Including Routing and Remote Access.
 
2. Are the latest drivers for the hardware installed?
 
3. Call PSS @ http://support.microsoft.com/default.aspx?scid=fh;en-us;Prodoffer02a#faq1399