hello when you do a clean install of the os you lose all the drivers even the ones for the mb. if you know the make and model of the mb i would look at the chipset it uses. make sure you installed the mb chipset drivers. if the drivers are installed right then you should be with the nvidia control panel or right clicking on the desktop check the color to 32 bits and the monitor res to a higher setting.
Heya, thank you so much for your help, sorry for the late reply - have been without internet for last few days.
Installed the recommended drivers as you suggested. The latest NVidia drivers still came up with the same problem. So instead I found the oldest Omega driver I could find (2009) and installed that. Voila!