Hi all this is my first post on here but i have been trawling the site for information on trying to fix my mac mini G4 1.42Ghz 512mb ram although ive forgotten what OS im running 
on startup im getting a grey screen with apple icon and then just the spinning wheel at the bottom.
so far i have tried:
booting in safe mode - nothing
Booting from install disc 1 - nothing (well just the grey screen with icon again)
booting with alt pressed down - it brings up harddrive, install disc and hardware test.
Hardware test - both quick test and extended test and everything passed.
NVRAM / PRAM - reset
PMU - reset
so now im at the point of being lost as what to do.
on startup im getting a grey screen with apple icon and then just the spinning wheel at the bottom.
so far i have tried:
booting in safe mode - nothing
Booting from install disc 1 - nothing (well just the grey screen with icon again)
booting with alt pressed down - it brings up harddrive, install disc and hardware test.
Hardware test - both quick test and extended test and everything passed.
NVRAM / PRAM - reset
PMU - reset
so now im at the point of being lost as what to do.