I have loaded a new LR from disc. Can import photo's in Library mode but when switching to Develop there is a bad rendering problem which makes Develop un usable.
All other modes show the image correctly.
I am running Windows 7 with Service pack 1 loaded.
Is there a solution or is it a faulty disc?
Turn off the GPU option in the LR preferences on the Performance tab.
Thanks to all for the reply.
Turned off the GPU and this solved the problem.