Ponderings and Random Thoughts

My home computer had been acting up for awhile now, and its now taken to either not turning on, or shutting off and rebooting after only a few minutes on. Not sure what’s wrong with it...nor how to fix it. I suspect it’s a hardware error, but I don’t know which bit. Err...help?

Edit: Working much better now. Thanks for the help! This machine has other issues, but at least its turning on now. --- Not sure if it will last but it's a good start. :)