Today I discovered that my C: drive on Windows XP Professional was missing approximately 2G of disk space. To my great surprise, I discovered that the System Restore service (SR) had gone berserk on me. This is how I remedied the situation and got SR working properly again.
To enable you to even see the System Volume Information folder used by the System Restore service, you need to open My Computer, go to Tools, Folder Options, View, then make sure there is no check next to Hide protected operating system files. Once you OK out of that, a number of additional folders should become visible in the root directory of your Windows drive. Each drive that has SR enabled, will have a System Volume Information folder on it.
Some of the symptoms of this are that the System Restore Service will not start, complaining "path not found." Gee, thanks for the helpful message. To see the services running and start one that isn't running, go to Start, Control Panel, Administrative Tools, Services. You should then see a list of all the services on your system and whether they are running or not. Another symptom is that if you go to Start, right click on my computer, choose Properties, then go to the System Restore tab, you get an error about RunDLL not being able to start. If you run Start, All Programs, Accessories, System Tools, System restore, it tells you "System Restore is not able to protect your computer. Please restart the system and try again." You can do this all day and the situation won't get any better.
What I found, was that if I attempted to view the System Volume Information folder on my D: drive, I got an Access Denied error message, even though I am using an administrator account. It turns out that the permissions for that folder are a little screwed up. Unfortunately this is where things get a little sketchy, because I wasn't taking notes, but it went roughly like this. Reboot XP, immediately press F8 and go into Safe Mode. Log in as Administrator. Open My Computer, open the D: drive, then right click on the System Volume Information folder and choose Properties, then go to the security tab. From there I found that it had "special" permissions for SYSTEM. I added full access for my user \COMPUTERNAME\ROB and \COMPUTERNAME\Administrator to the default permissions for SYSTEM. (A very odd process, involving typing in the user name then hitting a search button then checking some boxes.) I then rebooted XP, logged in as my regular user, and all of a sudden, I could access the files in D:\System Volume Information.
However at this point, checking back with Services, System Restore was still dead. So I took the plunge and deleted all the files from C:\System Volume Information and D:\System Volume Information. One file couldn't be deleted. I then emptied the recycle bin of 2.9G of JUNK.
I then went into services again, and to my great shock, I right clicked on the System Restore service, chose Start, and it did!
I then right clicked on My Computer, chose Properties, then went to the System Restore tab and it was all there. I changed the settings for disk space usage then went to check if Start, All Programs, Accessories, System Tools, System Restore worked, and it also did. I then created a Restore point, since by flushing the System Volume Information folders I lost all my previous restore points.
Lastly, I went into My Computer's Tools settings and turned Hide Protected Operating System Files back on. No sense tempting fate.
Now all is well. I made this article because two hours of searching the net didn't turn up a single answer to the many people who have the same problem.