So, you downloaded the newest, latest and greatest OS for your BlackBerry and have followed all the instructions found here.

1. Download and install Desktop Manager.
2. Download and install the OS of your choice for your device.
3. Delete vendor.xml located in c:\program files\common files\research in motion\apploader.
4. Plug in BB and open Desktop Manager.

However, when you open Desktop Manager you get no prompt to update. When you open Application Loader your new OS is not listed!!

This has been plaguing people for the last few months. I've never experienced the issue because of the way I've loaded Desktop Manager but Vasco at Horizon did and he and I together figured this out. I believe we've found the issue and will explain how to fix here.

The problem lies in the new Desktop
Manager's automatic "Check for Updates" feature. This feature uses your internet connection to look for OS updates for your device from your carrier. When it does this it loads a second virtual vendor.xml file in the temp folder on your computer (Vista users look in C:\Users\Username\appdata\virtualstore.) So, even after you delete the normal one that is installed with the OS and Desktop Manager, the automatic "check for updates" feature loads another one based on the brand of device you've got plugged into the PC.

To prevent this from happening this you need to install Desktop Manager WITHOUT this Automatic Update service. Below are the steps to remove this service.

1. Go to Control Panel >Add/Remove Programs.
2. Click on "BlackBerry Desktop Software" and select "Change/Remove."
3. When prompted, hit "Next" and then you should get options for Modify, Repair, or Remove. Choose "Modify."
4. On DM 4.7 and higher, in the list of installed items, you should see "BlackBerry Automatic Update." Click the icon next to it and change it to "This feature will not be available." That should put an "X" next to "BlackBerry Automatic Update." If you are using DM 4.6 or lower and don't see this option in this list then just continue with the install and the installation will ask you a few screens later. A screen will be shown where you will be asked to check the boxes for:

A) "Start BlackBerry Desktop Manager automatically each time the computer starts."
B) "Create a shortcut for BlackBerry Desktop Manager on the Windows Desktop."
C) "Check for software updates."

Be sure number 3, "Check for software updates," is NOT checked.

5. Finish the installation.

(Note: If you're doing a fresh install of Desktop Manager, be sure and choose the "Custom" install button so that you get the prompt for what features you want installed. Otherwise all the features will be installed as normal and you'll likely run into this issue.)

Once that is complete, you'll need to go back and search your computer for vendor.xml. When you do the search, make sure you click on "Advanced Options" and make sure that you search Hidden files and folders. This is important as some operating systems create a virtual store in the temp folder that this vendor.xml file is located in. You will not find this particular vendor.xml if you don't have hidden files/folders selected for search. Once the hidden vendor.xml is deleted it won't come back if you've reinstalled Desktop Manager without the Automatic Update Feature enabled.

Now, make sure your OS is installed (you may need to install the OS again, if you actually remove Desktop Manager and then reinstall Desktop Manager again. Make sure that you delete the normal vendor.xml file LAST before updating the device.

Tip of the day: Desktop Manager is not even required for doing an OS upgrade. In the same folder as the vendor.xml file is a file called Loader.exe. Running that will run apploader without Desktop Manager. It still makes the full backup and restore, but without all the DM stuff running in the background. I use this for all my OS upgrades. Then later I connect to DM to start my BES activation.

Can I just ask a question. If my laptop is being used by 2 BBs, does the deletion of the vendor.xml step need to be done when I am upgrading the 2nd BB?

Thanks a lot for that bro. Will flash my Curve 8900 tonight then.

thanks a million sonyclie77, lucky I found your thread, been stuck with the problem since yesterday!

I've flashed my BB 8900 successfully last night without any roadblocks. Didn't have to go through the procedure above so it's pretty straightforward.

Just one question, any of you having problems using Viigo? I can't seem to start Viigo as it just hang my BB. Tried reinstalling Viigo a few times but still the same case.

hi just want to ask, i got  a bb from a friend, he brought it from france and when i came back here i plug in a celcom sim-card but it cant detect the sim. why is this?

o last time he use 'orange provider'. can anyone help to use it with celcom?

Does it show invalid SIM on the phone's display?

Or the device may be locked to Orange.

To check, please check the following post, by achiko.

thanks ts.. flash my 8520 with no hassle!