How do you replace or upgrade the hard drive in the iMac G4 models? Which models support "big drives" and which do not?

The Apple Support Site provides instructions for installing RAM -- in the bottom "user accessible" slot -- as well as replacing the AirPort card in the iMac G4 systems.

However, Apple does not consider the Ultra ATA/66 hard drive in the 700 MHz and 800 MHz models or the Ultra ATA/100 hard drive in the 1.0 GHz and 1.25 GHz models to be a "customer-installable part" and declines to provide replacement instructions (Ultra ATA/100 drives are backwards compatible with the earlier Ultra ATA/66 standard, but will run at the slower speed). Consequently, EveryMac.com does not recommend that users attempt to upgrade the hard drive themselves.

The iMac G4 is a challenging system to upgrade the hard drive, and as such, users with limited experience upgrading computers would be wise to instead purchase an external USB or Firewire hard drive for a quick and easy storage increase. Even those with extensive experience upgrading systems might prefer to purchase an external drive rather than go to the trouble of disassembling and reassembling the computer.

Photo Credit: AccelerateYourMac (iMac G4 Opened)

Nevertheless, for the adventurous, the always excellent AccelerateYourMac has a detailed "take apart" guide for the iMac G4 that covers upgrading the hard drive. The Italian Faqintosh also has very nice step-by-step instructions.

Officially, Apple says that Macs running MacOS X 10.2 or higher released after June 2002 can use "big drives" -- those larger than 128 GB -- which would exclude the original iMac G4/700 (Flat Panel) and G4/800 (Flat Panel) models. However, third-parties have discovered that all iMac G4 models will support big drives running MacOS X 10.2 or later. For earlier versions of the MacOS -- including MacOS 9 -- a third-party driver, such as one from Intech is required to use hard drives larger than 128 GB.

Site sponsor Other World Computing sells internal hard drives for the iMac G4 models as well as quick-and-easy external USB and Firewire hard drives that will work with the iMac G4 as well as other Macs.