How Tomcat in Win2k/NT find JDK/JRE in non-existent directory???

I have downloaded, installed in Windows2000 Advanced Server
from binaries:
HTTP apache Server (from apache_1.3.22-win32-x86.exe)
jakarta-tomcat (from jakarta-tomcat-4.0.1.exe)
set TOMCAT environment variable.
It all worked I saw and played with examples of servlets and jsp.
But during installation jakarta-tomcat determined and installed JDK1.3 and JRE to directory which I did not use (installed by installation of JBuilder 5, Personal Edition while for using J2EE I needed JBuilder4 Enterprise Edition).
I uninstalled and deleted all:
Tomcat
Apache JBuilder5
restarted PC
reinstalled Apache.
BUT...
trying to reinstall Tomcat, the Tomcat installation gives a message
"Using Java Development Kit version 1.3 found in d:\JBuilder5\jdk1.3
Using Java Runtime Environment version 1.3 found in d:\JBuilder5\jdk1.3\jre\bin\classic\jvm.dll"
How does it come that Tomcat installation determines JDK in uninstalled, deleted, non-existent directories (while there is equivalent D:\JBuilder4\jdk1.3"???

Perhaps you have JAVA_HOME environment variable set?
This is not related, but you should have CATALINA_HOME set rather than TOMCAT_HOME.

No, JDK in Windows2K do not use any JAVA_HOME environment at all (I was using JDK for a year and do not have env vars set at all):
1)vars are used from registry. For ex., in
2)I have JDK in various palaces at my PC used by JBuilder4, JBuilder5, etc, and it is set-up by (installations of) those applications
3)Env vars are not set by the command set... what is different to prev Windows...!!!
What happened is that, using JBulder4 EE, I experimented to install JBuilder5. When I uninstalled it, Windows registry continued having the uninstalled/eliminated dirs, in
My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment\1.3.0 (JavaHome=old_dir; , RunTime Lib = ****)
My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit\1.3 (JavaHome=old_dir)
My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit\1.3.0 (JavaHome=old_dir)
My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Plug-in\1.3.0 (JavaHome=old_dir, RunTime Lib = ****)
My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Plug-in\1.3.0 (JavaHome=old_dir, RunTime Lib = ****)
etc., etc.
It was stupid to ask, since nobody can save your time here, only to waste even more