I am bundling SunJRE160_15Win32.vm jre for launching installer setup.exe.

Earlier applications used 64 bit ibm jre for launching setup.exe. Now if I do application upgrade using my new setup.exe (this has SunJRE160_15Win32.vm jre bundled ), upgradation will happen successfully, during upgradation I choose 64 bit Java VM for running my installed application. The application works fine post installation but during uninstallation, some of the file are not deleted/uninstalled successfully. Post un-installation, some of the files does remain in installed folder location.

My concern is:

Why the un-installation not happening successfully ?
Is there a problem in bundling of 32 bit sun jre for installing/launching my application on 64 bit Windows OS and then pointing 64 bit java VM for running my application ?