Upgrading Blackberry 8900 OS?

[chris]

Can anyone tell me how I can upgrade my Blackberry 8900's OS 4.6 to the latest one that has the threaded texting. I've literally tried about everything. Like I've downloaded those files from crackberry and everything, and installed them. It doesn't seem to show up on my Blackberry Desktop Manager, instead I found all the .alx files in:
C:\Program Files\Common Files\Research In Motion\Shared
I've tried like importing them using the Desktop Manager and the Loader program you'd find :
C:\Program Files\Common Files\Research In Motion\AppLoader

Additional info, I don't have internet subscribed on the phone if that makes a difference

[zbalat]

Go here to download OS v5.0 from your provider to your computer:

http://us.blackberry.com/support/downloads/download_sites.jsp

Double click the file you downloaded to install it on your computer

Plug your phone into your computer

Open Desktop Manager 6.0

Click Device - Update my device

Check the box next to OS 5.0

Click Install

If you don't have Desktop Manager 6.0 get it here:

http://us.blackberry.com/apps-software/desktop/

It's possible that your provider has not made OS 5.0 available yet.