The old Logitech Webcam drivers and RC 7100 problem.... a search before trying would have helped you out....
If you can manage to uninstall it I suggest upgrading to at least v7232 before trying again ot just wait and install the RTM by whatever means.
With the camera plugged in you can go to CONTROL PANEL>PROGRAM FEATURES and uninstall any software related to the camera.
Then open DEVICE MANAGER and uninstall 3 devices
Unplug the camera and reboot.
Run CCeaner and clean the registry,
You can then do an inplace upgrade to 7232 ot later and attempt to re-install with the "correct" driver which may be the one you tried to use with 7100.
Which driver did you try to install?
Restore your system as already suggested (much easier).
Edit: I could NOT get mine to work until v7232.