Thermal Expansion? or something else?

Hi iv got a semi weird question that id like to mull over...

1 of my home computers running XP, does seem to run hot to the touch as its now sumer time and i dont really have a choice but to keep it in a small un-airconditioned room

judging from Speed-fan iv noticed it in the past couple days get to 52 deg C range (not sure how accurate that is but it is a bit hot to the touch when i touch the back of the fan, or

now its never shut down or rebooted or anything of that nature, but laitly when i do turn it off for a period of time and try to restart it, it hangs on windows XP loading screen,

now intrestingly enough if i can still enter safe mode / ect , and iv tried resinstalling video drivers on a whim to see if that affects it, it seemed to fix it for the time but it still reoccurs on a cold boot...

iv also found that simply re-seating my video card a random geforce 4 420, that i pulled from an older system, this seems to let me boot up every time (simply reseating the card then powering it up again)

so im wondering if its Thermal expansion? (also note due to the design of my case its impossible for me to put a screw into the card slot for my video card... something that bugs me)

so im leaning towards thermal expansion, but could it also be a dying video card?

 

If you can enter safemode I doubt if heat is the issue. What CPU and motherboard?

 

Open the side of the case and run a box fan on the system. If that helps, it's a heat issue.