An error about deleting mpich2

When I delete the current version(MPICH2) and want to install the new version, a warning comes up:

"There is a problem with this Windows Installer package. A program required for this install to complete could not be run.
Contact your support personnel or package vendor"

It seemed to imply that my unloading was incomplete. I tried other ways to delete it, but it didn’t work.
I also installed and deleted many times on other computers before, but did not encounter this problem.
What can I do to solve this problem?
Best regards

This is a mailing list about LAMMPS, not MICH.