Ok so everything was running fine and dandy on my computer. Decided I wanted to upgrade my aging graphics card though, and while I was at it pop a bit more ram in.

So I buy both brand new from Overclockers at a good deal and get them installed.

The ram is the same speed and type, I simply swapped my 2x1gb sticks for 2x2gb (bringing it up to 8gb). Gfx card is PCI-E 3 and my board is 2 but that should be fine.

Got the latest drivers installed etc and it all goes wrong.

I can't install any programs if the file is on my C drive, but move it and I can install. It also blue screened twice regarding display drivers. So I roll back the driver to no avail. Everytime I try to install I get:

NSIS Error

Error writing the temporary file. Make sure your temp folder is valid.

I've tried removing the graphics card and ram (which are uninstalled now) and done a system restore ... same problem! Tried turning anti virus off too.

Now obviously I can work round it, but it worries me and is indicative of something being wrong. Any ideas?!