Today, for seemingly no reason that I can think of, some of my programs and games stopped working. It was only a few applications, but they all seemed to be missing info usually found in the registry (serial numbers, etc.). I started by doing a system restore back to yesterday, when everything was working fine, and it seemed to make things worse. Even more programs gave me errors and on top of that, I couldn't access the internet. I undid the restore and everything went back to the way is was originally (before the restore), thankfully.
I then went to the Add/Remove Programs tool with the intention to simply re-install the trouble-programs and saw something I've never seen before. About half of the programs in there didn't have information next to them, and when I clicked on one of them it didn't have a Change/Remove button next to it. Even those programs that had some info didn't have any modify or remove buttons.
For some of the programs that didn't work, I put in the original disc and ran the setup, giving me the option to Remove or Repair the software. When I chose either one, it began the process of uninstalling, but before it actually did anything I either (1) got an error saying the Windows Installer Service couldn't be accessed or (2) the setup was interrupted. I then tried a freeware program that I've used before (MyUninstaller) and nothing
showed up on the installed software list... very odd. I googled the Windows Installer error and found that it was a problem with registering the service. I followed the instructions found on the microsoft website found here
That worked for the programs that gave me the Windows Installer error. For the programs that gave me a "setup interrupted" error, I still haven't figured out how to uninstall them. As far as I understand the Windows Installer, it stores information in the registry for whatever programs you install with it (app location, uninstall location, etc.). For the software I have that uses Installer Vise software, there aren't any errors re-installing them, so I'm almost sure that it's a problem with the Windows Installer service (unless the other software doesn't use the registry). It's nothing critical, but for the software that gave me errors and won't run, and won't re-install on top of that, I'd like to know why. I'm concerned that it could be a permission problem with the registry, even a virus maybe. It would also be nice to be able to uninstall software through the Add/Remove Programs tool, instead of using the original setup files.
For some background:
I'm running Windows XP Pro SP2
2 GB RAM, plenty of HDD Space
I tried to make this post as precise and informative as possible. It's a little long, but hopefully somebody will read it through and be able to help me.