$ perl\bin\perl.exe -le "print for @INC"
C:/tmp/ActivePerl-5.10.1.1006-MSWin32-x86-291086/ActivePerl-5.10.1.1006-MSWin32-x86-291086/perl/site/lib
C:/tmp/ActivePerl-5.10.1.1006-MSWin32-x86-291086/ActivePerl-5.10.1.1006-MSWin32-x86-291086/perl/lib
.

$ rename perl 5.10

$ 5.10\bin\perl.exe -le "print for @INC"
C:/tmp/ActivePerl-5.10.1.1006-MSWin32-x86-291086/ActivePerl-5.10.1.1006-MSWin32-x86-291086/5.10/lib
.