Unable to reinstall WordPerfect Office 11

[John Hoffman]

I was having problems with WordPerfect Office 11 crashing
repeatedly. (I use in addition to MS Office XP because
some clients use MS and others use WP). I tried to
uninstall WP Office 11 using Add/Remove Programs. When
it would not uninstall, I deleted all the directories
with WP or Corel program files, and deleted all registry
keys for Corel or WordPerfect.

Now when I try to reinstall, the InstallShield Wizard
says "Another version of this product is already
installed. Installation of this version cannot
continue. To continue or remove the existing version of
this product, use Add/Remove Programs on the control
panel."

However, when I try to use Add/Remove Programs, I get the
message "Error 1706. No valid source code could be found
for WordPerfect Office 2003. The Windows Installer
cannot continue." When I click OK, I then get the
message "Error Number: 0x80040702. Description: Failed
to load dll:swcusten. Setup will now terminate."

How can I get WP11 to reinstall?

Any help would be MOST appreciated. I have spent hours
trying to solve the problem.

John Hoffman