As you have recently formatted the HDD it lessens the likelihood of malware and may point more to a bad update or driver.
As you can start the computer normally try running memtest86+
http://www.memtest.org/ a guide to how to
http://www.geekstogo...sing-memtest86/ if the Ram passes run the diagnostic tools for your brand of HDD
http://www.tacktech....ttid=287#maxtor
Another option you have is to reformat and add your previous software programmes one by one, putting the computer into hibernation after each one to see if the issue reoccurs, do the same with any windows updates by manually installing them one at a time, this will obviously take some time to complete but it may be the only way to find the cause, as a safeguard see the text below regarding malware;
If you suspect your system may have a malware issue I suggest you check out the self help guide at the malware forum
http://www.geekstogo...cleaning-guide/ if after following the guide you believe your system may still be infected you need to start a new topic there and not post any malware logs on this forum as they are not used here, provide them with a link to this thread to show them what if any steps have been taken.
Once you get the all clear from the malware guys if the issue is not resolved return here and someone will assist you.