I installed a wd hard drive. It keeps blinking, and holding down c with install cd leads me nowhere. It woun't repond at All! I really need to fix this machine, but nothing is working. has anyone had this happen?

First off is it compatible with a MAC? If it isn't then get one that does. If it does than try booting from bootdisks and formating the drive and partitioning it. The BIOS may not be able to recognize the hard-drive. Check apple support at www.apple.com

Uhm... if its ide it will work in a new mac... there is no true "Mac Compatable" for hard drives. If you can't even boot to a cd then make sure your hdd pins are set correctly on the ne drive.

You don't specify if this is a REPLACEMENT drive (you took your orig drive OUT and put this IN it's place) or an ADDITIONAL drive (mounted as a second hd). If it's a second hd you may not have set the jumpers for SLAVE mode. In the IDE scheme there is room for two drives. Master (main hd) and SLAVE (second hd). Conflicts = trouble. And another bit of advice (which may not be the case, but it can't hurt): Unplug all your USB and FIREWIRE devices from the USB & FW ports (except for the k/b & mouse of course) while doing all of this. I have had problems with things not behaving the way I know they should and that seemed to be the problem. I tried this out when unsuccessfully attempting to boot from a CD.

I also have just finished putting in a WD hard drive in my G4 (replacing the old one) AND all it does is blink ? to OS folder. Holding down C does nothing so I can't boot it up at all. Any help is appreciated

The three things make an IDE hard drive compatible with MAC OS are 1) it must support the "identify" command 2) it must perform at PIO mode 2 performance level or greater 3) write caching must be turned on. Ask the people you bought the drive from for help identifying which drives meet these criteria. Check the sonnet technologies (www.sonnettechnologies.com) site. In their compatibility matrix (fancy word for table. Their term not mine.) they list a couple of Westen Digital hard drives that are not compatible with their MAC IDE hard drive interface, called "Tempo". If your model is listed your may have to exchange it for a compatible Western Digital drive which they conveniently identify for you. Also check the Western Digital (www.westerndigital.com) site for info on your drives' compatibility with MAC OS.