new build freezing problem

[sc0rpion50]

so i built my self a new computer here are the specs. i5 4670k, msi g45 motherboard, 8gb corsair ram at 1600mhz, gtx 670, 64GB SanDisk, 1TB seagate HHD, h60 cooler, and 750w psu. i built the computer and everything went smoothly, easy build didnt run into any problems, used the ssd to put the operating system on (win7 ult) and the hhd for everything eles. took a while to get it to find the hhd in computer but it did after some tweaking. it worked fine for the first week i had it, no problems, and the temps on everything where low, 37 idle for my cpu. i was downloading all my games off steam and so i left my pc on for 7-10 hours for 3 days in order to download them. on the last day it had just finished downloading all my games and i had to go out for 3 days, so i didnt get a chance to play any of them. when i came back i turned on my pc to find my cpu temps where higher 45+ on idle, nothing too high, but when i would run a game they would get to around 90, nothing too major but i just need to remount i think. but everything i went to open or close a program it would freeze and lock up, some programs would woek while other would not, skype wouldnt not want to work at all as it would not send message, and crash when i would go to open up a window, the mouse and everything would then freeze, it did this for alot of programs, but the once that work would also randomly lock up when i tried to do anything on them. but it only does this sometimes, never all the time, i can turn the pc on and it will be fine running at low temps and run everything, but sometimes i turn it on and nothing works, it it at high temps, it locks, up freeze, and crash. the temps i get are not like they should be causing the freezes? my though are that the cpu or my motherboard is fault? i have no idea what could be causing this. someday it can be fine other it isnt. any ideas guys?? also when it is having one of its phases it wont connect to the internet. i am out of idea's

[WoodenMarker]

Does it seem like the pump on the H60 is failing?

[ttam]

Make sure that your cooler has a firm fit on your cpu and also make sure that it's finger tight. There is a chance it's way to loose or just way to tight.