Clean installation was done, yes. All temp. files from previous installations were deleted as well (AppData etc).
SL with FS was working fine before with these specs (FPS wise). The i3-2100 is a Dual Core running @ 3,1GHz..
We also tried Singularity with no luck. Internet is cable connected, WLAN is not in use!
The low FPS are constant at just vary between 1-5 fps which is normal depending on
camera angle but it happens on every sim. At my home, in a sandbox, everywhere.