I already have "C:\Strawberry\perl\bin" at the top.

But is that where dlltool.exe is found? You can use the Windows cmd.exe utility where to see all the locations of a given executable in your PATH -- in the order found; the first one listed will be the one that it runs. On my system, I only have one (with my highly-customized berrybrew wrapper around Strawberry perl):

C:\>where dlltool
C:\usr\local\apps\BERRYBREW\perls\system\c\bin\dlltool.exe
[download]

I believe in a default Strawberry installation, the equivalent would be C:\Strawberry\c\bin. Note in Strawberry's portableshell.bat, they use set PATH=%~dp0perl\site\bin;%~dp0perl\bin;%~dp0c\bin;%PATH% -- they add three directories to the path. So if I were you, I would add set C:\Strawberry\perl\site\bin;C:\Strawberry\perl\bin;C:\Strawberry\c\bin all before %ORACLE_HOME%\bin.

(note: I do not know if the anonymous monk is looking down the right solution-trail, and whether fixing your PATH will solve your underlying problem. I just wanted to point out how to find out what copy of an executable is first in your PATH , and how to set your PATH so that all the Strawberry executables come before any that might be in the %ORACLE_HOME%\bin)

--
update: clarified the parenthetical