System Drive letter

In Disk Management section of Computer Management, Drive C is correctly
identified as my system disk, but in System Restore Drive D is identified as
the system disk (as it was at one time). How do I make System Restore
correctly identify Drive C as the system disk? Right now System Restore does
not work at all with both drives connected and if I disable the D: drive,
System Restore fails to run.
The three required boot files are all correctly found in the root directory
of the C: drive.
This is the report I get from Event Viewer:
Event Type: Error
Event Source: SRService
Event Category: None
Event ID: 104
Date: 7/28/2008
Time: 8:28:57 PM
User: N/A
Computer: STUSPEECEE
Description:
The System Restore initialization process failed.

For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.
Data:
0000: 03 00 00 00 ....


Any help will be greatly appreciated.

--
Stu B.