I have three problems which result in the 0x80071a91 error message and seem to be related to transaction support/resource manager. I found several KB articles and comments in this and other forums and tried the various fixes - none work - each is a pre-SP1 fix.

My Vista system is: Factory Installed Vista Home Premium 64 bit SP1 with all updates on Gateway 4 core processor and less than three months in use.

PROBLEMS:
1) Attempting to run Backup at the point where the settings are to be saved.
KB 939615 - Cannot change the settings for a file backup operation or use the Windows Task Scheduler to change the defrag schedule in WIndows VIsta. Transaction Manager Fix - 0x80071a91 error. Recommended fix is:
fsutil resource setautoreset true c:\
2) Attempting to delete a task
Transaction support within the specified file system resource manager is not started or was shutdown due to an error. (0x80071A91)
3) Attempting to link to on-line error message from the event viewer.
Clicking on "on-line event" closes the event manager snap-in
Msesage: Unhandled Exception in Managed Code Snap-n - HRESULT 0x80071A19.
"This snap-in performed a non-valid operation and has been unloaded-
Exception type: Syustem.Runtime.Interop.Services.comexception - HRESULT 0x80071a91."

A fourth problem may or may not be related - when I try to start Wsearch (Windosw Indexing Services) it stops within 3-5 seconds with the error msgs - 0x80040d23, 0x8007007e (VSS) finally 0x80071a91.and Events ID 1008, 1015, 1004 and 1008.

Yes, I have run SFC twice, tried many suggested fixes, etc.
I also attempted to do a 'refrech' install of Vista; it ran 60 minutes, seemed to comple successively, and then ended with an error and finally restored to prior system.

I have so many deeply rooted provlems that I know that a refresh restore is the right way to go, if only I could get one to complete.

I am highly reluctent to do a clean install because of programs and data.

Sorry, forgot to mention that I do not have any system restore points which go back to a date prior to my problems.

Thanks, Aaron. A Full Factory Restore to my Gateway (clean install) is probably the only way I am going to get back to 100%.

(Note: All of your personal data files and applications will be lost. Be sure that you have your data files backed up before performing this option.)

I have several more ideas as to how to fix the specific problems and, as you can probably understand, am highly reluctant to do a clean install because of my personal programs and data.