I installed 4.5.0.42 Beta from a friend who worked for RIM before. I found the beta version doesn't work well. I can't get voice mail indicator on this version. Could anybody tell me how I can downgrade to an old version OS? I want to have clean installation of the original version.

Thanks,

It's simple to downgrade. However, I do have a workaround for the voicemail indicator, if you're interested...

YouMail - Cell Phone Voice Mail with Personalized Greetings and Online Retrieval

Works awesome! I get an email with a transcribed message of the voice message as well as a .wav attachment that I can listen to if I want to. I can also just call in and listen normally, too. I switched and I probably won't be switching back even after they fix the voicemail icon.

However, to downgrade, simply do the following:

1. Uninstall the .42 version from Control Panel >Add/Remove Programs
2. Install the version you want loaded on the device.
3. Delete vendor.xml file (if you use a TMo released version, this isn't necessary)
4. Plug in BB and run DM/Apploader. It will "downgrade."