I downloaded the celtex-2.9.7.exe application and as usual tried to double click to run, but I got a warning screen saying 'do you want this programme from an unknown publisher to make changes to make changes to this computer?' and no matter how many times I click yes, it just brings me back to the screen I started from - no unpacking of files, nothing. I'm getting really frustrated by this and googling the matter doesn't seem to help. The programme seems compatible with this OS from what I can see.