Please provide more information.To what would you like to upgrade it?
Since OSX Mavericks was just announced, I'm going to assume that's what you're wanting to upgrade to.
Not all Macs can run Mavericks.
Mavericks Capable Macs
Mavericks, like its predecessor Mountain Lion, requires one of the following Macs with at least 2 GB of RAM and 8 GB of available hard drive space:
- iMac (Mid 2007 or newer)
- MacBook (Late 2008 Aluminum, or Early 2009 or newer)
- MacBook Air (Late 2008 or newer)
- MacBook Pro (Mid/Late 2007 or newer)
- Mac mini (Early 2009 or newer)
- Mac Pro (Early 2008 or newer)
- Xserve (Early 2009)
If your Mac isn't one of the ones listed above, you won't be able to upgrade.
If you have an iMac, MacBook, MacBook Pro, or Mac mini model that was originally released in Early/Mid 2006, the latest version of Mac OS X your system supports is Snow Leopard.http://store.apple.com/us/product/MC573/mac-os-x-106-snow-leopard