GauravK wrote:
I think your 3.6.8 download may be corrupt because Sourceforge's servers suck and truncate the download halfway through. Try choosing a different download mirror from Sourceforge and download 3.6.8's installer again. That should allow you to remove 3.6.8. The $Menu issue happens when the INI file, C:\Program Files\Classic Shell\StartMenuL10N.ini, which stores language strings is damaged. Removing 3.6.8 and updating to the latest 4.x release should fix all problems.
Ok, so it turns out I was downloading the wrong file apparently? (idk I was downloading the 3.6.8, this time I tried the 3.6.8-ru. Not sure what the difference is). And when I try installing it, it gives me a different error message. I did try different mirrors with the 3.6.8 installer though, I still get that invalid installer message.
This is what it says trying to open the 3.6.8-ru installer;

But, this just goes back to the problem of trying to uninstall through windows add/remove programs;

edit: I just tried copying the same installer over onto my pc, and running it (i'm having problems on my laptop, not my pc) and it's working fine, I don't get that invalid installer error. Could it be an issue with Windows 8.1?