Error message with Microsoft Word

Hope someone can help me. When I open a Word document I get this message:word could not create the work file. check the temp environment variable.

I use Windows 8. What I have tried:

Deleting the file in safe mode so I could delete in normal reboot. Downloading it again. I cant save alterations.
I also tried moving the cache but cant find the correct folder: net cache.

Thanks for any help in advance.

 

Thanks, I did try that link but didnt have the folders I needed to find to sort it. I did unistalled Word 2013 and reinstalled Word 2010 and its fine now.