Windows "Device Installer" Errors / SFC Not Available...D'OH!

This error has probably existed for quite some time, but I did not notice it until I tried to install a piece of hardware (Fragpedals).

Then I got these:

Device installer error: Windows could not load the installer for mouse. Contact your hardware vendor for assistance.

Device installer error: Windows could not load the installer for keyboard. Contact your hardware vendor assistance.

I tried to reinstall Windows Installer and also get the following error messages:

Device installer error: Windows could not load the installer for keyboard. Contact your hardware vendor for assistance.

Device installer error: Windows could not load the installer for mouse. Contact your hardware vendor for assistance.

Device installer error: Windows could not load the installer for SCSIAdapter. Contact your hardware vendor for assistance.

Device installer error: Windows could not load the installer for hdc. Contact your hardware vendor for assistance.

These are the only errors mentioned.  

I tried to use Windows' system file checker and got this message:

Windows File Protection could not initiate a scan of protected system files.

The specific error code is: 0x000006ba [The RPC server is unavailable.]

sfc.exe is version 5.1

I found a page in Microsoft Support that relates to Windows 2000.  XP and 2000 are both based on NT, so it should relate:

http://support.microsoft.com/kb/296241

I followed the instructions regarding VeriSign time stamping.  The service is there, but it says it has expired.  I'm not sure what to make of this.  Most of what I've found says it doesn't matter that the certificate has expired.

On August 15, the event log started showing this error message:

The time service has not been able to synchronize the system time for 49152 seconds because none of the time providers has been able to provide a usable time stamp. The system clock is unsynchronized.

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

Could this have something to do with the VeriSign Time Stamp?  The suggestion for fixing the VeriSign Time Stamp involves access to another computer running Windows XP.  Unfortunately, I don't have such access.

There were numerous "fixes" on the Internet that I've tried, but so far none of them have worked.  I can't remember all of them.  I should have written them down.

Further info:

Yes, the RPC service is running, both the Remote Procedure Call and the Remote Procedure Call Locator.

I have renewed root certificates in Add/Remove Windows Components

I've tried

sfc /scannow /revert
sfc /scanonce
sfc /scannow /purgecache
sfc /scanboot

Other things I've tried:

*Ran a thorough CHKDSK
*Scanned for Malware
*System Restore (several days back)
*Other stuff I can't remember

Incidentally, when I tried to run the configuration utility for Good Works System Fragpedal Elite, I got an error message:

10:10:15 PM

8/30/2007 10:10:15 PM  RunTime Error in RTR-720ConfigUtil

RunTime Error: 339 - Component 'tabctl32.ocx' or one of its dependencies not correctly registered: a file is missing or invalid
      Module Name    : loading
      Procedure Name : finish_init
      Line Number    : 118
      Error Source   : Gamingmouse
      User Desc.     :
Microsoft Windows XP Professional Service Pack 2 (Build 2600), service pack 2.0, CM version 1.05.007
Call Stack:
      Module    : loading
      Procedure : finish_init()

      Module    : loading
      Procedure : kickoff_timer_Timer()

I've done some Googling, but most of what I've found pertained to specific software and not a general error. Any help would be greatly appreciated because I don't want to do a clean installation of Windows.

I suppose my next step will be a repair installation, but those haven't worked for me in the past. :(

Windows XP SP2
Manufacturer:        
Ladyhawk, INC
Processor:      
Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz (2 CPUs)
Memory:      
2048MB RAM (DDR2-666)
Hard Drive:      
Seagate 320 GB
Video Card:      
Radeon X1900XT
Monitor:      
SyncMaster 204T/204Ts/204B,SyncMaster Magic CX201Ts(Digital)
Sound Card:      
Realtek HD Audio output
Speakers/Headphones:      
Keyboard:      
nostromo speedpad n52
Mouse:      
Logitech G7
Mouse Surface:      
Ratpadz Slicked with Armor-All...w00t!
Operating System:      
Windows XP Professional (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_qfe.070227-2300)