I cant install any 3G modems anymore

I have exactly the same issue as this guy http://www.tomshardware.com/forum/70...nymore-windows So I cannot install any 3G modems, and win7 says that the drivers could not have been installed. However I have tried the solution in the thread I pasted, but the registry value is correct for me. I'm hopeless with this thing.

So you are saying your registry already has the "Installer32" entry w/ value "mdminst.dll,ClassInstall32" but still you have a problem installing 3G modems?

Here is my Registry for that section, see if maybe you have other differences ...

(click to enlarge)

I have these same values. But I have this key 0001 which seems to be some kind of mobile phone bluetooth modem. Is it safe to just remove this key? Or is it even possible that it interferes new modem installation?

Make sure you have uninstalled the driver.

Select the 001 and see if you get a permissions error (I know I do on the Properties one). If you don't get an error then export it first (File - Export) so you have a back-up. Then delete it.

Then try to install the driver.

It worked when I deleted the 0001 key. Thanks a lot!

Glad it worked out for you.