first things first:
1: get the latest os for your device
check out this thread:
2: while that is downloading I'd recommend getting DM 4.5 but if you have 4.3 it will work just fine (note: DM= Desktop Manager)
if you need\want to upgrade go here:
just click on the pull down menu and select the appropriate DM
now after you have run and installed both of these things you will need to look into
"C:\Program Files\Common Files\Research In Motion\AppLoader" and delete a file labeled
Hook up your BB to your computer and back it up. it will probably tell you that there are system files that it needs to update. you can either confirm the update (which will take you to a screen that will ask you if you want to back your BB up, select yes) or you can cancel and back up your BB. Either way make sure you back up your BB.
Just in case something goes wrong and you have a backup you needn't worry.
if you decide to let it update your phone right away, after it makes your back up continue through the rest of the screens and it will load the new OS onto your phone. DO NOT INTERRUPT this process the phone needs to remain hooked up to your computer while it is loading the new files. it will restart and have the Hour Glass for a long time DO NOT disconnect your phone. not until it returns to the normal home screen should you remove your USB cable. If you go this route after the phone returns to the home screen it should have all of your contacts and personal info restored on the phone automatically.
If you decide to make a backup yourself (non automated) after the back up is complete go into app loader and continue to the next screen and it will tell you that there are system updates available for the phone. continue through and it will start removing old OS files and putting new ones on. once again DO NOT REMOVE the USB cable until this process is finished. it could take up to 30min maybe even 45 (I doubt the 45) just be patient (note: if you make your own backup and then go through app loader to put the new OS on your device, after it is finishes updating you will need to load the info from your backup file to get your contacts, E-mails, calendar stuff and whatnot back)
for a bit more info check out this thread:
I hope this helps somewhat.
let me know if I can be of any assistance to you
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my pin: 31a52e1c