Unable to load LE 8 or 7

[Kluson]

Hi

I have been having trouble with pro tools LE and hope some bright spark can help.
I am running vista SP1, my pro tools was working fine and I haven't used it for a while> I recently wanted to run it, but it wouldn't load. I downloaded the upgrade LE8 from my amnesty, but couldn't get that to install.
I now removed everything from my PC relating to digidesign and thought I would go back to LE7 which worked great.
When I install the disc I get a message saying

" digidsesign audio drivers appear to be installed on this computer, the protools driver versions are not compatible with installed digidesign Audio drivers.
Please use uninstall or change a programme control panel to uninstall the existing Digidesign audio drivers and restart this computer before installing pro tools"

If I go to the uninstall programmes from the control panel, I cannot find anything relating to digidesign or pro tools.
Can anyone suggest where I can find the driver or should I try to download and install LE8 again?

please help if you can

kind regards
Dave