This Knowledge Base article (KB12450) is an excellent article for confirming where the current installation of the JRE is.

Warning: The following procedure involves modifying the computer registry. This can cause substantial damage to the Windows operating system. Document and back up the registry entries prior to implementing any changes.

Download the update you wish to install on the BlackBerry Enterprise Server.

Confirm the current settings:

• Open a command prompt on the BlackBerry Enterprise Server (Start -> Run -> cmd) and enter “java -version”. This will report the current running version.
• On the BlackBerry Enterprise Server, browse to c:\Program Files\Java\<version>\bin\client. Right-click on jvm.dll and select Properties. Click on the Version tab and select Full Version.
• Open the Registry on the BlackBerry Enterprise Server (Start -> Run -> regedit). Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BlackBerry MDS Connection Service. Double-click on ImagePath and locate the path to the jvm.dll.

Export the Registry for these keys (right-click and select Export) as a backup:

• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BlackBerry MDS Connection Service
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BlackBerry Collaboration Service

Perform the installation/upgrade.

Update the settings in the Registry.

1. Log into the BlackBerry Enterprise Server as the BlackBerry service account (BESAdmin).
2. Open the Registry and browse to these keys:
   • BlackBerry MDS Connection Service : HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BlackBerry MDS Connection Service
     Double-click the ImagePath string value and update the jvmpath variable to the udpated location of jvm.dll. Do not change any other settings.

   The value of this REG_Expand_SZ should be similar to the follow:

   ” C:\Program Files\Research In Motion\BlackBerry Enterprise Server\MDS\bin\bmds.exe” -s jvmpath=”C:\Program Files\Java\jre1.6.0_02\bin\client\jvm.dll” -XX:+DisableExplicitGC -Xss128K -Xmx768M -Xms128M classpathdir=”C:\Program Files\Research In Motion\BlackBerry Enterprise Server\MDS\classpath\\” wrkdir=”C:\Program Files\Research In Motion\BlackBerry Enterprise Server\MDS\Servers\BESNAME1\\” webserverdir=”C:\Program Files\Research In Motion\BlackBerry Enterprise Server\MDS\webserver\\” -rbes “BESNAME1_MDS-CS_1”

   • BlackBerry Instant Messaging Connector : HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BlackBerry Collaboration Service
     Double-click the ImagePath string value and update the jvmpath variable to the udpated location of jvm.dll. Do not change any other settings.

The value of this REG_Expand_SZ should be similar to the follow:

” C:\Program Files\Research In Motion\BlackBerry Enterprise Server\BBIM\bin\bcol.exe” -s jvmpath=”C:\Program Files\Java\jre1.6.0_02\bin\client\jvm.dll” -XX:+DisableExplicitGC -Xss64K -Xmx512M -Xms128M classpathdir=”C:\Program Files\Research In Motion\BlackBerry Enterprise Server\BBIM\classpath\\” wrkdir=”C:\Program Files\Research In Motion\BlackBerry Enterprise Server\BBIM\Servers\BESNAME1\\” -feature cwa -rimbes “BESNAME1_BBIM_1“

After making the above modifications and pointing to the updated versions of the jvm.dll files you must restart the modified services.

[Quelle: blackberry.com]