How to perform a clean reload of the BlackBerry Device Software using the Application

Requirement:

BlackBerry Desktop Manager software 4.1 and later
BlackBerry Device software
BlackBerry smartphone
Windows based PC with USB port and BlackBerry data cable

If you do not have BlackBerry Desktop Manager and BlackBerry Device software installed on your computer then you can download it from HERE. Once downloaded, remember to install first the BlackBerry Desktop Manager and then Blackberry Device software.
Procedure:
Note: You should not install BlackBerry Device Software that is earlier than the version installed on the BlackBerry smartphone. Doing so could cause the BlackBerry smartphone to malfunction.
For e.g. On your BlackBerry 8310 if you already have V4.5 device software then there is no point in installing V4.2 device software, doing so could cause the BlackBerry to malfunction.
Before proceeding, make sure that the latest version of BlackBerry Device Software is installed on the computer by completing the following steps:

Open BlackBerry Desktop Manager.
Click Help.
Select About Desktop Manager from the menu and click the Device Software tab.
Confirm that the BlackBerry Device Software displayed is the latest version currently available from the w s p.

1) Back up the BlackBerry smartphone before proceeding
BlackBerry device users can perform a full or selective backup of the data using the Backup and Restore tool in BlackBerry Desktop Manager by completing the following steps:

Connect the BlackBerry device to the computer running BlackBerry Desktop Manager
Open BlackBerry Desktop Manager
Double-click Backup and Restore
Select Backup to perform a full backup or select Advanced to perform a backup of specific databases
Choose a location to save the backup file, then click Save

2)installation process:
To perform a clean install of the BlackBerry Device Software using BlackBerry Desktop Manager 4.5, 4.6, 4.7 perform the following steps:

Connect the BlackBerry smartphone to the computer and open BlackBerry Desktop Manager
Double-click the Application Loader icon
Click Add/Remove Applications
Type your BlackBerry smartphone password, if prompted and click OK
Click the check boxes next to the names of the applications you want to load
Click Settings,*(Desktop Manger 4.5 & 4.6 has Options tab below instead of Settings) and then click the check boxes beside Delete all application data and Erase all currently installed applications

Click Ok -> Next
Click Finish. It will take atleast 25-30 minutes to complete the entire process. During this time, make sure, your computer is ON and BlackBerry remain connected to the computer.
When the process has completed, the message The loading operation was successful will appear. Click Main Menu to return to BlackBerry Desktop Manager

Note: The Delete all application data and Delete all currently installed applications options are not available when using the Application Loader in BlackBerry Desktop Manager 4.5. To workaround this issue, use the Application Loader standalone file by performing the following steps:

Open My Computer (or Computer on Windows Vista).
Navigate to C:\Program Files\Common Files\Research In Motion\AppLoader
Run the Loader.exe file and follow steps 3 through 9 to complete a clean installation of the BlackBerry Device Software.

3) How to restore data or databases from backup files to BlackBerry smartphone
To restore all the data in the backup file to your BlackBerry smartphone, complete the following steps:

Connect the BlackBerry smartphone to your computer
Open the BlackBerry Desktop Manager
Double-click Backup and Restore
Click Restore
Navigate to the backup file you want to restore to your BlackBerry smartphone
Double-click the backup (.ipd) file (Created during Step1)

To restore specific databases in the backup file to your BlackBerry smartphone, complete the following steps:

Connect your BlackBerry smartphone to your computer.
Open the BlackBerry Desktop Manager.
Click Backup and Restore.
Click Advanced.
On the File menu, select Open.
Double-click the backup (.ipd) file. (Created during Step1)
In the Desktop File Databases section, select the database(s) to restore. Click the right arrow button. Note: If the right arrow button is unavailable, see the Additional Information section in post.
Click Yes.

Additional Info
If your BlackBerry smartphone is associated with Server software version 4.0 or later, and your BlackBerry smartphone user account is set for automatic wireless backup, the right arrow button will be unavailable when you attempt to manually restore most databases. To restore these databases manually, complete the following steps:

Delete the Desktop [SYNC] service book from your BlackBerry smartphone. On your BlackBerry smartphone, go to Options > Advanced Options > Service Book, Highlight Desktop [SYNC], display the menu and select Delete
Connect your BlackBerry smartphone to the computer.
Restore the databases using steps 1 to 8 in the procedure above.
When the database(s) are restored, open the Service Book screen on your BlackBerry smartphone.
Display the menu and select Undelete. The Desktop [SYNC] service book is restored