Hi Serene,
A system restore is unlikely to fix this kind of problem.
If someone mistakenly tried to fix things by running an AC install, chose main computer, gave up, and left an incomplete or corrupted install, then lots of settings and files are wrong and will prevent a clean uninstall or reinstall. It's a client, not a server.
There are other explanations for the situation, but that's what I see routinely in offices with everything from printers to anti-virus to EMR programs. No one means to pound a square peg into a round hole, but it's terribly easy to do with a keyboard and good intentions. Most recently I met a server where a 64-bit printer package had somehow been installed on a 32-bit server.
The Windows system restore tries to restore registry entries (and possibly some files, depending on programs and settings) that may have worked earlier, but will no longer work with the files left behind by a failed install (which may claim to uninstall, but invariably leaves lots of settings and files that programs like Revo offer to remove).
(In contrast, restoring an image backup of the partition would have put things back to where they were.)
***
If AC seems to be back on the computer after the system restore and still failing . . .
Download the free Revo uninstaller:
https://www.majorgeeks.com/files/details/revo_uninstaller.htmlTell Revo to uninstall AC and anything that looks like AC. It will first run the AC uninstaller, just like Windows. Give it some time and minimize or move windows around to see if there's some stupid pop-up window hiding underneath that says are you sure you want to uninstall AC?
When that part finishes, choose the Revo advanced option and tell it to get rid of all the leftover files and registry entries that it sees. It will grind away for a while and show one window after another, asking you to mark the files, folders, and registry entries that you want to remove. Some of them may require a restart before they can be removed.
Alternatively, the AC uninstall may say that it can't run, in which case you choose the forced-MSI uninstall on Revo's options.
Almost worst case, you delete all the AC files and folders by hand and delete all the AC entries in the registry with regedit.
Worst case, reinstall Windows, run the endless Windows updates, install printers, install AC as a client.
For practice and to see how Revo works, you can download a utility like CCleaner or Wise Disk Cleaner, install it, and run Revo to uninstall it.
Again, this is a client computer, not a server/main computer. The whole problem started with a failed install of AC as a server that quit or failed before getting the SQL Server installed.
Cheers,
Carl Fogel