Windows Installer is effed up

[Vegeta897]

I can't run any MSI based installations, whether they're .exe or .msi.

I get this error almost immediately after launching an installer:

This installation package could not be opened. Verify that the package exists and that you can access it, or contact the application vendor to verify that this is a valid Windows Installer package.

I've tried installing the latest .net framework and windows installer versions, as well as a system restore to a date where I didn't have this problem. I've tried most solutions I could find through googling. There's even an official windows installer cleanup program, but I can't even install that because I get the same message.

I can't even think of any reason this problem arose. I haven't made any changes to my system that I know of.

Help would be greatly appreciated.

 

[DEATHMASTER]

so you tried a bunch of different ones? Maybe system restore could still help (in case its a change you're not aware of)

 

[Vegeta897]

Well I tried restoring to a date well before I ever saw the error, but I guess it's still possible something could have happened before that. I'll try going back as far as I can, just to see if it will even fix anything. Good thing I can always undo and have everything back the way it is now.

Edit: No luck.

Edit 2: I did a repair install on my OS and it works now. Yey.

 

[bodhi]

theres an app from microsoft that supposedly fixes problems with the windows installer, but when ive tried it on clients machines its not worked. i would backup your stuff and do a complete restore.

edit: i stupidly stopped reading halfway through the post above and didnt realise youd solved it. that will serve me right for being lazy

 

[Vegeta897]

And I already mentioned the app that fixes windows installer in my first post.

There's even an official windows installer cleanup program, but I can't even install that because I get the same message.