Well folks, like many of you I had all but abandoned my hopes of running PIA or any other VPN on my Windows 7 laptop. No matter what I did, I would always end up with the same, frustrating error - TAP driver failed to install.
Today I finally got it fixed, and it was fairly simply.
1. Backup the registry (regedit > export)
2. In start>run>cmd>regedit, browse to the following registry entry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Network
3. Rename the key called Config to Config.bak
4. Re-run installation software (I used openVPN, but PIA should work too)
Hopefully this helps someone, as I spent a lot of time cussing at my computer and raising my blood pressure, all the while support not giving me a lick of help.
I've just used this solution on my Windows 8.1 machine and it worked.