How can I change between different JRE in the Same PC

Question

I have two systems.A system can only run in JRE 1.3 and B system can only run in JRE 1.5 enviroment.But I have to run both in one desktop(which use WinXP SP2),how can I do it . I tried to edit the system config using the cmd of regedit , edited some like these.But it did not work .Could anybody tell me how to do? Thanks a lot in advantage.
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{08B0E5C0-4FCB-11CF-AAA5-00401C608501}\TreatAs]
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{8AD9C840-044E-11D1-B3E9-00805F499D93}]
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{8AD9C840-044E-11D1-B3E9-00805F499D93}\InprocServer32]
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\JavaPlugin\CLSID]
[HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit]CurrentVersion="1.X"
[HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment] CurrentVersion="1.X"
The information of operation system is omitted.
Message was edited by:
daiwill
Operation System is WinXP SP2
Message was edited by:
daiwill

Answer 1

I found some clues last week in these linkes.
http://forum.java.sun.com/thread.jspa?threadID=657406&tstart=150
http://java.sun.com/j2se/1.5.0/docs/guide/deployment/deployment-guide/jcp.html#java
Which has the contents like the below:
Example:
Assume you are running on Microsoft Windows with Microsoft Internet Explorer, have first installed version 1.4.2, then version 5.0, and you want to run 1.4.2.
Go to the j2re1.4.2\bin directory where JRE 1.4.2 was installed. On a Windows default installation, this would be here: C:\Program Files\Java\j2re1.4.2\bin
Double-click the jpicpl32.exe file located there. It will launch the control panel for 1.4.2.
Select the Browser tab. Microsoft Internet Explorer might still appear to be set (checked). However, when 5.0 was installed, the registration of the 1.4.2 JRE with Internet Explorer was overwritten by the 5.0 JRE.
If Microsoft Internet Explorer is shown as checked, uncheck it and click Apply. You will see a confirmation dialog stating that browser settings have changed.
Check Microsoft Internet Explorer and click Apply. You should see a confirmation dialog.
Restart the browser. It should now use the 1.4.2 JRE for conventional APPLET tags.
I tried the method of change the control panel but they did not work either.
Any other helps?
Thanks in advantage.
Message was edited by:
daiwill