Java HotSpot Virtual Machine

i am having the wizard type setup file of TOMCAT 5.0
i have installed jdk 1.5 on my system.
but while installing tomcat it gives me error " Java virtual machine not found "
when i see
jdk/bin
jre/bin/client/jvm.dll
etc in my JAVA folder in program files.
java is running fine.. checked that by entering javac in dos.

i tried all permutation combinations with my environment variables.
classpath and path had the address of the lib of jre as well as the jvm path as well as the jdk/bin path.
java_home was set properly.
later i tried to install it after deleting both from the environment variable section.

nothing really seems to work out here.
i tried the same versions of JDK and Tomcat on another workstation and it installed properly.

it is giving my problem out here on a different notebook with same environment ..(both have windows xp service pack 2)

can anyone help me out here!!

thanks in advance.