Okay, can i ask i am on orange, and i have now downloaded it from the link but everyone mentions the vendor x something file. do i need to remove this, and hooow!
Usually, the Vendor.xml file is located at C:\Program Files\Common Files\Research in Motion\AppLoader. You can safely remove this, simply by selecting the file from Windows Explorer and hitting the Delete key on your keyboard. Once you have done this and you have installed the 5.0.0.509 OS for your BlackBerry, proceed by launching Loader.exe from the same directory (make sure to connect your BlackBerry via USB first).
Re-read the directions that afropoika gave you. You can see that vendor.xml is on your PC. Deleting it will have no negative effect. Not deleting it will mean you cannot install the alien OS.
Vendor.xml identifies the carrier that issued the device. The Loader program checks vendor.xml for that information, and won't load an OS from a carrier other than the one specified in vendor.xml. If vendor.xml is missing, then any carrier's OS will be accepted. It's not so much a security function is it is a configuration management tool for the OS.
Okay, thats all sorted but how come when i try to do it on the update thing then do it, it comes up but if i select it and click next it says no update needed when im clearly running 4.6
I can't understand your problem from your description. Did you double-click the OS download to install it? Did you delete vendor.xml? Are you following a step-by-step procedure to upgrade? The "Upgrade / Downgrade" procedure that's linked in my sig is almost user-proof, and is better than an ad-hoc approach. I'll be out for a while and won't be able to answer more questions.
Even if your not here, thanks. I think the problem was the fact I was using the DM to do it, because as soon as i used the loader method, it worked perfectly. I just assumed the loader thing you discussed was the application loader, thanks again.