There should be a little icon in your system tray labeled BB Device Manager. Right click on it and choose properties. Near the bottom of the dialog box you should see a check box where you can disable it from starting with windows.
Make sure your Desktop Manager is open then right click on the icon in the system tray and select properties there will be a box that says beside it start desktop manager when windows starts or something similar..... uncheck it.
I am having the same problem and i swear i can't find that little icon, could it be that this is a different version of desktop manager? I just got the phone from verizon 3 days ago...help would be greatly appreciated!
In Add and remove Programs, whe you click remove Blackberry, an option pops up to Modify the Blackberry softwore. Click modify and proceed. You will be prompted to/and uncheck the box to open desktop manager at startup. Continue with the nodify, have your install disk at hand.....Voila the desktop manager will not load at startup. This will take care of your issues.