Should I upgrade or fix my computer?

I've had this computer since 2007, but upgraded the memory, the power supply and the video card. I'm still running most games on high/medium settings, although with dx9 since I don't have a windows 7.

I got home from work a couple of days ago to see my computer running a chkdsk on all the drives which took all day. Once it was done it was at windows but none of my usb ports worked, so I restarted it and it was attempting to boot intoa floppy or cd rom drive. I went into the bios and it had my hard drives rearranged, showing my old ones as the first boot drives. So I fixed it in the bios, restarted, and it froze while posting. After restarting it, it had not posted, and even if I start it without a video card or memory, it doesn't beep. Cmos reset doesn't fix the problem, and I've tried older memory sticks and a variety of memory slots to no avail. The last time this happened it was the power supply, but this one is fairly new, probably less than a year old.

So, I'm looking for opinions. Should I upgrade my cpu, motherboard and memory or just try to fix whatever is wrong with it?

It's most likely the motherboard.

And that's a good reason to upgrade the OS (64-bit), CPU and RAM with it...

Agreed. Failing that, it seems like a good excuse to invest in a brand new one.

Good point. First it was the motherboard, to which a similar thing happened. The replacement board was fine, then the ram was bad, then the power supply. Safe to say it's the motherboard again.

Looked online yesterday at deals. I ended up getting an AMD FX 6100 and an Asus Crosshair V mobo that should arrive today. I'm going to Best Buy to see what their DDR3 prices are like as I couldn't purchase any in time to make the shipping deadline to get it before Thanksgiving.

I may have messed up. I read that the motherboard needs a bios update or else it won't post with the AMD FX processors. I don't have an AM2/AM3 processor to use in order to flash the bios. Asus is trying to get new boards shipped with the bios upgrade. I hope I got one of them, otherwise it was a waste to ship it so quickly, as I will have to ship the motherboard back to Asus to get one with the proper bios.

*insert standard benji ASUS rant*

After having upgraded my PC half a gazillion times, I wouldn't get anything from AMD-ATI ever again, too many issues and constraints...

I'll keep that in mind if I run into any issues. My second pc was an athlon xp 2500 that I had clocked to the xp 3200 speeds with some low latency ram and an ati 800 platinum video card, and an audigy 2zs. It ran pretty damn awesome up until '08 or so.