Do you think if I disable it, it might affect in a unsatisfactory way, the operation of other system programs, eg. the Registry?
In a word: No.
I have never found a satisfactory reason to use or reply on System Restore, when other, much better options are available for true system restoration, with such typical examples including Drive Image and Norton Ghost.
My advice: Kill the service, regain any lost hard drive space previously used, and invest in a decent program for OS recovery. Just backing up the Registry isn't enough, not if your system experiences file loss or corruption, such as might occur with a virus. Backing up is more than just saving references to system file locations, or even just recovering original Windows system files ... it should encompass <i>all</i> files, including those that come from Windows Update, and even those installed by third-party software.
One viable backup made by an imaging program can and will save you many, many hours of grief. With it, you can forget about formatting and reinstallations due to hardware issues, viruses, or even common user error.
Example: I recently had to repair a system that I had last seen in May. The computer had over 350 spyware programs running at the boot, and three Trojans.
Attempting to remove the spyware/malware caused the display area to become blank, and lock up the system.
I could have fought the computer for several hours, in a vain attempt to repair all the damage ... but, I happened to have created an image of that system after the last repair, when all the files and programs were still in a defragmented, pristine condition.
And so, I backed up whatever recent, important data I could pull off the drive, replaced the partition with the image, and every single problem was solved. The restoration took about 10 minutes, and saved the client quite a bit of cash, as I didn't have to devote those many, unnecessary hours to the repair. All I really had to do was add a few updates, install a new, updated firewall, Anti-Virus program, and popup killer.
And, BTW, all of this was a heck of a lot faster than formatting and reinstalling the OS from scratch.
When I was completely finished, I used Drive Image to backup the C: partition once again.
Some programs are worth an investment, and a good imaging program can be worth it's weight in gold. It could very well become the most important tool in your arsenal when a system goes haywire, and all other possible repair solutions end up requiring some kind of data loss, and/or many hours troubleshooting.