Won't install - 0x8007645 - tried everything I can find

My definitions suddenly wouldn't update a few days ago, so I tried to uninstall MSE. It wouldn't uninstall, so I ran Microsoft Fix. That didn't solve it, so I started doing everything I could find, including everything on this page:

http://answers.microsoft.com/en-us/protect/forum/mse-protect_start/uninstalling-mse/a63b8c4b-58ed-437e-8086-fa08d80725a4

I ran offline defender (from USB), but my PC is clean. I've never installed any other anti-virus. MSE appears to be uninstalled, but it still won't re-install - I get error 0x0070645.

The last recommendation on the page is to "open a support case." That's what led me here.

What's a good next step?

Thanks in advance,

Craig

View this thread