Unearth,
Go behind the back of your PC and see if the fan on the back is running. Considering the age of this PC, it's not unlikely that the power supply fan or CPU fan has stopped spinning. Overheating could be the cause of your problem. I would also recommend opening up the case of your PC and checking to see if the fan mounted on the CPU is working. In addition, the PC is likely full of dust and dirt if you haven't cleaned it out before. If you're unfamiliar with opening up your PC - reply with the exact HP Pavillion model and I can find documentation to guide you through removing the case.
All of that said - your problem might also be due to some virus or malware. I would still check out the things I discussed above - but I'd also post your original message to:
http://www.techsupportforum.com/secu...this-log-help/
The tech folks who manage this forum can assist you in running malware/virus detection software in case the problem is due to a virus and not hardware failure or overheating.
- John