SUMIF Error When Clicking The Formula Tab?

[JDobbsy1987]

Hi,

Can someone help with the below please, this is with Excel 2007?

I can open Excel fine but as soon as i click on the formula tab i get the attached error (see capture.jpg)

after that has happen i cannot write in a cell with the error attached coming up (see capture2.jpg)

These are new excel documents and have not had any macro's put in, just gone to start and opened a new excel 2007 sheet

Do you have any idea how to stop this?

So far i have tried:
1. Tried creating a macro workbook but still get the error
2. Tried re-installing office 2007 which didn't fix it

Regards,
JDobbsy1987