4.5 has been release for 8300
BlackBerry Handheld Software v188.8.131.52(EastAsia) (Includes English)
Package Version: 184.108.40.206
* Applications: 220.127.116.11
* Software Platform: 18.104.22.168
* File name: 8300EastAsia_PBr4.5.0_rel52_PL22.214.171.124_A126.96.36.199_S tarHub.exe
* File size: 75.6MB
To install this software on any 8300:
1. Download and install the latest Desktop Manager. Click here
2. Download and install the OS packaged linked above.
3. Delete the vendor.xml file located in c:\program files\common files\research in motion\apploader
4. Connect BB, open Desktop Manager and you should be prompted to upgrade.
The process takes about 45 minutes to an hour depending on how much data you have to backup and restore during the process. Once it's done loading the new OS it will reboot (it may do this twice during the entire process.) You will see a white screen with an hourglass for up to 20 minutes at a time while the DM says "waiting for initialization."
If you end up with a white screen with small icons and the number 507, simply connect to DM again and run application loader again and it should load the OS to the device.
(Link to previous 188.8.131.52 OS Click Here
.) This particular version was known to damage sim cards on some TMobile devices requiring the sim to be replaced during beta testing. TMobile users load at your own risk.
*Note: Also, on all devices it's a good idea to make a backup of your media card before loading OS 4.5. Constant reboots can occur when using media cards formatted in OS 4.2 or 4.3 in OS 4.5. Then reformat the media card in OS 4.5 and restore your data.
*Note: While in Application Loader be sure and check to boxes to add Documents To Go to your device. Failure to install Documents To Go will cause java errors in some 3rd party apps.