Update/upgrade older iMac

Question

I'm a computer novice. My older iMac is no longer able properly to use many current websites and I get messages saying update to safari of firefox; but to get current versions of safari or firefox I need something beyond Mac OS X v 10.1.5, my current configuration. I've searched the Mac website, but it presuppose a starting point of at least version 2.0. How do I get where I can begin to go farther? Thanks in advance for any help!

Answer 1

Welcome To  Discussions schuler!
Here is a recap, of some of the info, in the previously posted replies, and also additional info.
Mac OS X Versions 10.1, 10.2, 10.3, and 10.4, are complete system upgrades that must be purchased.
Once an OS has been installed, the point upgrades, such as 10.1.x to 10.1.5 (Final) 10.2.x to 10.2.8 (Final), 10.3.x to 10.3.9 (Final), and 10.4.x to 10.4.10 (Pending), can be downloaded for free.
Jaguar, Panther, and Tiger 10.4.x, are no longer available directly from the Apple Online Store, as Leopard 10.5.x, will be the most up to date OS, when it is released, on 10/26/07.
But, if you know what to look for, the Jaguar Full Retail CDs, a Full Retail Version, of the Panther Install CDs, or a Full Retail Version, of the Tiger Install DVD, can be purchased less expensively, at some online Apple retailers, Amazon, eBay, FastMac, HardCore Mac, etc.
Be sure not to purchase grey, upgrade or machine specific CDs or DVDs.
Jaguar and Panther are only on CDs, not DVDs.
The discs should look exactly like the images in the above links, and not say Upgrade, CPU Drop-in DVD, or "This software is part of a hardware bundle purchase - not to be sold seperately." on them.
Additional info in these links.
Using OS X Install CDs/DVDs On Multiple Macs
What's A Computer Specific Mac OS X Release
Software Update, Upgrade: What's The Difference?
Caveat Emptor! Examine these items very carefully, and if in doubt, ask questions of the seller before purchase!
Jaguar On eBay
Panther On eBay
Tiger On eBay
Before upgrading to any OS X version, check to see if your Mac needs a Firmware Update.
If one is required, you must start the computer from a Mac OS 8 or Mac OS 9 System Folder on the computer's hard disk, not from a CD, in order to install it.
Also check to see if your Mac model, is listed in this KB Article OS X Must Be Installed On First -8GB Partition.
Once Jaguar 10.2.x is installed, you can use the 10.2.8 Combo Update,
or if Panther 10.3.x is installed, you can use the 10.3.9 Combo Update, to upgrade to the final version of either OS.
If your Mac meets the Tiger System Requirements, you could also consider installing that, and then use the PPC 10.4.10 Combo Update, to upgrade to the current version.
Jaguar System Requirements
-Power Mac G3 or G4, iMac, eMac, PowerBook G3 or G4, or iBook computer
-128MB of physical RAM
-Supports all video cards shipped by Apple on Mac OS X-compatible systems. Quartz Extreme functionality is supported by the following video cards: NVIDIA GeForce2 MX, GeForce3, GeForce4 MX, or GeForce4 Ti; Any AGP-based ATI RADEON card. A minimum of 16MB VRAM is required.
-QuickTime Pro functionality requires a QuickTime 6 Pro key. The QuickTime 5 Pro key will not work after this software is installed.
-DVD Player requires a DVD-ROM equipped Macintosh with built-in FireWire.
Review these Apple documents for Panther System Requirements
Additional Panther System Requirements.
Additionally, Tiger 10.4.x ships on a DVD, so if your Mac doesn’t have a built-in DVD-ROM player, you will have to use an alternative method of installation.
Info here Installing Tiger Without A DVD Drive,
and here Installing Tiger Using Firewire Target Disk Mode.
The Tiger Media Exchange Program, referred to in that article, is no longer available.
Shop Carefully, Examine All Documentation, And I Wish You Success!
ali b