45c is very cool for a GPU
But a 6450 is very weak hence the lag
ive been playing it fine for a few weeks
Have you checked the temps of your other parts (CPU, HDD, etc.)? Also what antivirus do you have? Be sure to do a virus scan on your pc.
i have done a few full scans with AVG over the past few days and i have checked the other temps and at the moment they are
and i was playing about an hour ago and since then all i've done is listen to songs on youtube. i also yesterday did a disk defrag and that didn't do anything.
Well those temps seem to be ok. Have you installed any new mods to Skyrim? Also does this happen with other games and programs or just Skyrim? Also if you don't already have these: http://forums.steampowered.com/forums/showthread.php?t=3097857
Try if any of those could increase your fps.
EDIT: As stated in the comment above, check your ram usage. How much ram you do you have?