Sounds like you have either installed an corrupt theme or you attempted to do an update/restore and it was interrupted.
You will need to first make sure you have the latest version of BlackBerry Desktop installed:
Attach your BlackBerry to your PC via USB cable.
Next, click Start -> All Programs -> Accessories -> Command Prompt
cd\ (press enter)
cd program files (press enter)
cd common files (press enter)
cd research in motion (press enter)
cd apploader (press enter)
loader.exe /nojvm (press enter)
The Application Loader Wizard will appear, click Next.
In the Connection drop down, you should see USB-PIN: UNKNOWN. Click Next.
**You should see the default BlackBerry apps, just click Next -> Finish.
Now wait and be sure to let the entire process complete.
**If you do not see a list of applications mentioned above and instead see the message "The BlackBerry Desktop Software does not have BlackBerry Device Software for the device that you have connected. Contact your wireless service provider or systems administrator." -> download the BlackBerry's operating system for your carrier and device below.
After obtaining this, you will need to follow the steps above.
This should resolve you issue. Thank you for using JustAnswer.
Okay. Go back and do through the process again. When it gets to the point of showing the applications, uncheck all that you can.
You may have a program that is either faulty or incompatible with your BlackBerry.
In my experiences, I have fixed maybe 50+ Blackberries with the "White Screen of Death" with only maybe 4 or 5 that could not be recovered.
I am going to opt out and hope any expert will be able to help you.