I jsut installed mac for liek the tenth time, well tried to, now for the first time I got it to startup, sort of. It gets to the grey screen with the grey apple then after loading for a while its got that circle with the line through it. what does that mean and how can I resolve this problem, I'm using mac on pc so It's kinda hit or miss I know but this is install disk and version number three. the other two I tried didn't even work.

You should probably looks elsewhere for help on installing MacOSX on anything other than a Macintosh computer (Try Osx86).

which version of mac are you trying to install? Is it leopard, tiger .etc.

failing in the gray screen is much like getting the windows "NTLDR NOT FOUND".

the boot loader can not find the Mac kernel.

As you are on a foreign platform (ie Intel - non-Mac hardware) you will have
extra steps to make this work.