Can't install Parallels Transporter Agent on PC

Recently bought new mac and Parallels Desktop Switch to Mac version. Installed Parallels Desktop 4.0 on to Mac
no problem but Transporter Agent keeps giving an Error and won't complete to install on the PC.

ERROR 1720
A script required for the install to complete could not be read. Custom Action
Search_OldTransporter script error 2146827859, Mi...

Went to support page but the folder they say I should open in the InstallShield Installation Information does not exist on my computer. They give no other suggestions. Any suggestions?