Thanks to you both again for your efforts (and patience). I will try this when I get back to my workstation - from memory, I was able to run linear regression and other modules without error, so I think you might be onto something with how my institution handles security. I'm not sure if I mentioned it on here, but in order to install R packages onto base R we had to set up an environmental variable.
I'll report back
Cheers,
Dave
