Problem with G5

[G5Unit]

It has been going wird on me ever since I pluged in an epson R300, or around since then. iTunes stays open sometimes saying it is not responding and I can't close it. Fans go really fast sometimes. Everything is glitchy like the clock froze and I pressed restart and it restart in like 2 seconds. I pressed shut down and it restart. Can't be hardrive space issues because I stil have 40 gigs left. Could it be SPYWARE! Or just plain hardware problems? Is it time to upgrade to Tiger? Please help me!

 

[CanadaRAM]

It's not spyware.

Go back to the basics: Shut down,
Unplug all peripherals other than mouse & Kbd., including Firewire drives.

Boot from the OS CD (DVD) and do a verify and repair on the drive
Then reboot and Repair permissions

Does it run properly?

Add one peripheral, reinstall its software if any (check for the latest web updates) reboot, test.
repeat