help rebooting

[thesss]

ok i bought a case for a computer to fit in a small space on a friends desk, put together a sempron 2800, even took out the crappy ASYS power supply and replaced it with an antec 400w, so anyway i had the computer running fine for like 3 days, went to the computer today and it said the cpu was at 85c, so i shut her down, added a fan made sure the heatsink(thermaltake silent power) was seated, rebooted, and again the same issue happened that happend to my friends last computer that we scrapped. the computer goes past the bios, then to the windows load with the blue bar crossing the bottom, then once it passes that reboot. and it can go in a circle all day, i dont know whats wrong because this is 2 completly seperate computers that have eventually dont this and i dont know what to do. any suggestions..?

 

[CrAzY_GaMeR_07]

where they located in the same places??

if so move it to another room for the night and try in the mourning...

(You did use thermal greese...?)

~Joe