I am not offered the option to install from an INF context menu.

Start the registry editor (regedt32.exe)

Move to HKEY_CLASSES_ROOTinffileshell

Check for a sub-key "Install", if it does not exist select "Add Key" from the Edit menu and enter a name of Install.

The default entry from Install (called ) should be &Install. If it does not exist select "Add Value" from the Edit menu, do not enter any name, select type REG_SZ and click OK. It will then ask for a string which should be "&Install" (don't actually enter the quotes). Click OK

Under the Install key should be another key, command. If this does not exist, again create using "Add Key" from the edit menu.

Under the command key should be a default value (called ) which should have the data "%SystemRoot%System32rundll32.exe setupapi,InstallHinfSection DefaultInstall 132 %1" in it. The the default key is missing exist select "Add Value" from the Edit menu, do not enter any name, select type REG_EXPAND_SZ and click OK. It will then ask for a string which should be "%SystemRoot%System32rundll32.exe setupapi,InstallHinfSection DefaultInstall 132 %1" (don't actually enter the quotes). Click OK

Close the registry editor