I have isolated the problem to Microsoft Security Essentials - when I open Excel it hangs and tells me that the program is not responding, I cannot print any more and I cannot open Devices and Printers, it just spools the green line at the top.
I went to MSE > Settings > Real Time Protection and turned off the tick box. I was then able to access Excel normally and likewise open Devices and Printers.
I re-booted and then found that MSE had ticked itself back and that I was again unable to access Excel and unable to access Devices etc.
What do I do to fix this?
I also before doing this ran Excel without Addins, I also checked that my Windows updates were up to date, I also created another user for my machine, I also scanned pc from the command prompt - neither of these had any effect. I am convinced that MSE is the issue, but what do I do? I cannot run it without real time protection can I?