can i upgrade my 10.4 to a 10.6 ????

If your Mac meets the hardware requirements for Snow Leopard 10.6

• Mac computer with an Intel processor
• 1GB of memory
• 5GB of available disk space
• DVD drive for installation

then you can call Apple and order an install DVD for it.

Allan

Since you make absolutely no mention of which model computer you have we cannot say.

1) Make sure your computer meets Snow Leopard technical specifications - http://support.apple.com/kb/SP575 This mostly means making sure it is an Intel Mac and has at least 1GB RAM (more is recommended). To check RAM, go to the Apple in the upper left corner of any window, then "About This Mac". Now continue to "More Info...". It should say you have at least 1GB of "memory".

2) Apple no longer carries 10.6 in its stores or online. Telephone Apple to purchase a Snow Leopard disc. In the USA: (800) 676-2775 (contact information for other countries: http://support.apple.com/kb/HE57)

Alternatively you can buy from online retailers but anticipate paying much more than the original price which is the price still charged by Apple

3) Backing up your computer before upgrading is always a good idea.

4) After installing from the DVD, update your Snow Leopard installation using Software Update or manually downloading and installing the Mac OS X 10.6.8 Update Combo v.1.1 - http://support.apple.com/kb/DL1399

Get more information about your computer. Go to the Apple in the upper left corner of any window, then "About This Mac". Write down what it says about "version"and report that here. Now continue to "More Info..." Copy and paste the information here, but omit the serial number and Hardware UUID (if present).

Do you have an Intel Mac? 512MB sounds low to me for any Intel Mac. If you get information as I instructed it will tell you if you have a dual core or dual core2, both of which are Intel, or a PowerMac which is not. If you have an Intel Mac you can consider buying new RAM.

http://www.mac-sales.com Other places too but OWC has pretty good telehone support.

http://www.crucial.com

• sry , i have a 1.83 ghz intel core 2 duo
• macintosh hd

You still haven't identified your Mac, i.e., MacBook, MacBook Pro, MacMini, iMac, etc.

Repeating what Limnos asked you:

Get more information about your computer. Go to the Apple in the upper left corner of any window, then "About This Mac". Write down what it says about "version"and report that here. Now continue to "More Info..." Copy and paste the information here, but omit the serial number and Hardware UUID (if present).