Where can I download Mavericks 10.9.0?

Back up your data, check your applications for compatibility, and download Mavericks from the Mac App Store.

I strongly agree with everything Niel has advised!

Some Macs capable of running 10.6.8 cannot run higher versions of the Mac OS, or are limited to 10.7 max. Check the Mavericks system reqs before going farther:

http://support.apple.com/kb/HT5842

Do you really want too? I did & now my mac runs really slow & wont open many files, when I asked an IT expert he just said "welcome to the club" . im my oppinion this is a big mistake on apples part. I am going back to snow leopold asp.

Instead of whining and complaining, It would help us to help you if we could have some more technical info about your iMac.

OS X Mavericks isn't your problem!

It is what you have installed on your Mac that is causing all of your system issues.

Please, PLEASE start your own, NEW discussion thread instead of hijacking this OP's. thread.

If you wish, Please download, install and run Etrecheck. Etrecheck was developed as a simple Mac diagnostic reporting tool by a regular Apple Support forum user and technical support contributor named Etresoft.

Etrecheck is a small, unobstrusive app that compiles a static snapshot of your entire Mac hardware system and installed software.

This is a free app that has been honestly created to provided help in diagnosing issues with Macs running the new OS X 10.9 Mavericks.

It is not malware and can be safely downloaded and installed onto your Mac.

http://www.etresoft.com/etrecheck

Copy/paste and post its report here in another reply thread so that we have a complete profile of your Mac's hardware and installed software so we can all help with your Mac performance issues.

Thank You.

You can't. Only 10.9.3 is available from the MAS.