I googled and binged for a long time today to make it work. Finally it all paid off with some R&D. Here are the steps:
0. I was using jrockit 64 bit version. You can use any JVM.
1. Download 64 bit tomcat zip version from apache tomcat web site. I took the latest one.
2. Extracted tomcat in a directory
3. Installed jdk and set java_home and jre home properly.
4. Downloaded 64 bit tomcat6.exe etc from this path:
http://svn.apache.org/viewvc/tomcat/tc6.0.x/tags/TOMCAT_6_0_16/res/procrun/
I downloaded amd64 ones and put them in procrun dir of bin dir. If there is no procrun dir then create one in bin.
5. Open service.bat of tomcat. It is there in tomcat\bin directory.
6. Go to line:
if exist "%CATALINA_HOME%\bin\tomcat6.exe" goto okHome
replace it with:
if exist "%CATALINA_HOME%\bin\procrun\amd64\tomcat6.exe" goto okHome
replace all such occurrences.
7. Go to line where it has jvm.dll as below:
set "PR_JVM=%JAVA_HOME%\jre\bin\jrockit\jvm.dll"
Make sure that the path to jvm.dll is correct. Double or triple check it. This is the most important thing.
Echo this path and test if required.
8. All set. Now run the command in bin directory of tomcat on a command prompt as below:
service install <your-service-name>
9. That's it.