Is better to use Windows for update..

Mac is not recommended...
Yes you can. Just follow the instruction and guide on how to download and install it..

Your DM dont allowed to download because your set are not original and it is an AP Set...

Upgrading Procedure for an Official OS release is as follows:

1. Download the OS and install it on your PC. (Make sure you have already removed any older OSes you have installed on your PC by going to Add / Remove Programs in Control Panel)

2. Delete the vendor.xml file (located in C:\Program Files\Common Files\Research In Motion\AppLoader)

3. Backup your 3rd party applications ( optional recommended step )

4. Connect your BlackBerry to your PC and right click on a file named Loader (located in the same place where you found the vendor.xml > C:\Program Files\Common Files\Research In Motion\AppLoader\Loader.exe) and select '' Run As Administrator ''

5. Follow the prompts and make sure you select the languages and applications you wish to be installed.
The Loader will backup and restore your data by default.
Still Having Issues !!?
I would recommend using BBSAK to Upgrade, so

- Uninstall the OS(s) you already have installed on your PC
- Delete the folder (research in motion) in ( c: \program files\common files\research in motion )
- Restart your PC