Q: Is a 9 year old mac too old?

"9-year old" doesn't pin down your iMac sub-variant, something we need to know to see if you have any upgrade path left.  We should be able to give a more definitive answer by learning the sub-variant, plus checking for known slow-down suspects and problem software, hard drive condition, and whether you can add RAM if you do this:

Please download and install this free utility that will safely reveal those things we need to know to help, and nothing else:

http://www.etresoft.com/etrecheck

It is secure and written by one of our most valued members to allow users to show details of their computer's configuration in Apple Support Communities without revealing any sensitive personal data.

Run the program and click the "Copy report to clipboard" button when it displays the results. Then return here and paste the report into a response to your initial post. It can often show if any harmful files/programs are dragging down your performance.

Thanks!

Upgrade the RAM. While 2GB is sufficient to install Yosemite if you want to run anything in addition to Yosemite more RAM is needed.

Also remove Genieo with the direction at http://www.thesafemac.com/arg-genieo/

this page would have the availability for the macs that could go to yosemite

How to install OS X Yosemite on your Mac - Apple Support

the oldest one that it can go to though is 2007 so it would be able to go to yosemite but i would guess that this would be the last update for that mac.

typically after 8 years is when it is a good time to start looking at getting a new computer when you are comparing that computer to a newer one it will of course be slower because of the advances in the technology. your mac should be able to run yosemite but to update it would have to go to mountain lion or mavericks first since 10.5.5 doesn't have the app store to be able to instal with. if the mac is something that you would actually use daily or use for work i would recommend to update to a better system if possible. if you don't have high use on that mac then you would be fine to update the mac but i would expect it to possibly run slower.

Genieo is adware that is definitely slowing your computer a bunch. The link the other Allan posted has removal instructions, as does this Apple article:

Remove unwanted adware that displays pop-up ads and graphics on your Mac - Apple Support

If neither of those is clear to you, you can use this utility developed by one of our most respected security experts:

AdwareMedic

Your have other stuff installed that will slow your Mac:

1) Western DIgital software that came with your Passport external drive is pretty useless and can slow you down. First see it the CD take came with teh drive ahs an uninstaller program. If not, you can do it manually. Double-click your hard drive and, in the new window, double click the System folder. Inside that one is a folder labelled "Extensions." In it are the two extensions that need to go:

  com.wdc.driver.1394HP (1.0.9)

  com.wdc.driver.USBHP (1.0.11)

2) teh DivX player can slow yo udown if not updated. IF you use it, update it from tis web site. If yo udon;t use it get rid of it.

Adding memory (RAM) is an easy at-home job; Last summer my 13-year old grandson who had never been inside a computer upgraded the RAM is Gramma's iMac in less than ten minutes. Video instructions are here:

http://eshop.macsales.com/installvideos/imac_mid_2007_mem/

You can install up to 6GB RAM but understand the jump from 4GB to 6GB results in a higher cost/GB in your particular model--not the usual situation. Four GB will probably be fine.

I've spent my Mac life keeping older Macs in service. "Time for a new one" is the easy answer that ignores your easy-to-remove kludge apps and a lack of RAM..As long as your needs are basic, getting rid of the cr@pware and adding RAM should keep yours working nicely for some time to come. The 4GB RAM upgrade kit for your model costs about US$55 from the RAM vendor I use:

http://eshop.macsales.com/shop/apple/memory/iMac/Intel_Core_2_Duo

That should be your only expense.

Don't let hard drive get much more full. you have 74 GB free now but, the smaller that gets, the slower the computer can become. Use that external drive to off-load stuff yo udon't use a lot.

With only 2 GB of RAM, that machine is barely able to run Yosemite at all. As others have pointed out, you could upgrade the RAM... but you'll have to make a decision about whether or not that is a worthwhile expense on a computer that's so old.

If you have the budget to replace it, you'll be blown away by the speed of the new Macs. You'll wonder how you ever managed with that old one.

If you don't have the budget to replace it, and you're not necessarily married to the idea of keeping Yosemite on it, you could downgrade. Personally, on a Mac that old, I'd probably be inclined to just put Snow Leopard (Mac OS X 10.6) on it.

If you don't have the budget to replace it, but you've absolutely got to have Yosemite, you'll probably need to install more RAM. You'll also want to see some of the other comments about removing some of the software you have installed.

Hi Allan;

I read this post today when searching with similar issues. I have the Etrecheck report ready. Should I post it here?

As one can never know if the setup and resulting problem is exactly the same, it is best to start your own thread instead of adding to someone else's as it can get very confusing, explain the problems you've experienced, and paste the report.

thomas_r really is right. With 2GB Snow Leopard really is the last OS you can run well on that computer. If you are willing to upgrade the memory to either 4 or its maximum 6GB you can upgrade it to 10.8 (Mt Lion) and have it run nearly as well as Snow Leopard. It was when I upgraded to Mavericks (the version before Yosemite) that my 2007 iMac felt slow and old. Personally I think the RAM upgrade and OS upgrade to 10.8 is worth it but if you were happy with 10.6 and the software that you could run on it that’s also a good solution - as long as you can live with the fact that there are no more security updates coming for 10.6 or its software.