If the plugs show up in PT, doesn't that mean they are installed?
Try this if you haven't already, it's a fix for european systems:
(On that page, click the orange text saying "Pro Tools crashes on European Windows OS")
http://www.wavesupport.net/SpecialPa...arch=european#
My waves 8 was unstable, both GUI and operation, until I applied the fix.
Apparently the plugs need US formatting of numbers and decimals to function.