i have a imac desktop, its a g2, a g3, im not sure.... well it turns on, and it seems to load, but when it is done loading,an error seems to pop up... its like a rectangle box, with a pickture of a bomb lighting up, anf it says... Sorry, a system error occurred "finder" error type 10,then it has a restart button, and when i click it it just freezes... can some one helpme please...

The bomb means a serious unrecoverable error has occured. I haven't used OS 9 on a daily basis in about 8 years so your best bet would be support.apple.com they should have some legacy document that may be able to help you. I'd wipe the drive and start fresh but it could be something else check that site I gave you first.