Using version 4.2I with D7 professional

Have been using this for 2-3 weeks for a new project but for the last
few days have been using another PC and D5 to work on an existing
project. When I returned to the PC with D7 and started D7, the error
message "Can't load package c:\program files\borland\delphi7
\projects\bpl\IBO40CDT_D7.bpl.
One of the library files needed to run this application cannot be
found" was displayed. This was repeated for every DT package that was
loaded in the component pallette. I de-installed IBO and then
compiled IBO40_D7 which worked. However when I tried to install the
first DT package, the same error message recurred. I then restored
all of the IBO files from the IBO and IBODCU zip files and tried
again with the same result. Any suggestions? I notice that this
question has been asked before but no answer was forthcoming.