Is there a timekeeper program

Is there anything that can work like hourmeter for your pc. It will run anytime the machine is powered up into running and keep a record of hours the machine is working. Maybe even session time and wel as accumulated time.
I thought it would be a good way to gauge component life.

Yep.

The task manager (ctrl - shift - escape).

Go to performance tab.

Edit - Oh, you mean accumulated hours running in total forever? Yes, I'm sure it exists but not that I can say off the top of my head.

Anyhow, it's not too reliable a way to gauge component life.

A machine that never reboots is going to outlast a machine that is constantly powered off and booted cold. Heating and cooling, the actual changing in temperature, is what does components in much quicker than actual use.

True, I realise it would only be a rough estimate but still handy to know.

Yeah, yeah...would be cool to have, no doubt. I hear that.

I would be willing to venture a guess that Windows itself knows this figure and it can be extracted somehow by a simple software to report. Or there may even be some secret Windows command that only 1/1,000,000,000 know that could report this.

Answers That Works has a program called "The Ultimate Troubleshooter". It has that feature, a disk cleaner, lists all computer hardware, rates Services and Startup programs that should be dealt with. I've been using it for about 3 years now. It works in x86 and x64 versions of Windows. I'm not positive, but it costs either $29.95 or $39.95.