Your options are to upgrade to a suitably built newer Perl, or build it yourselfI think that if the error is "The application failed to start because MSVCR90.dll was not found", then there's a very strong chance that this can be fixed by simply placing MSVCR90.dll in the path - which is what
Anonymous Monk suggested (in not so many words, of course ... as is his charter :-)
Upgrading to a newer version of ActivePerl is unlikely to help as it, too, will have been built using MSVC++ 6.0. Nevertheless, the approach that gives best mileage is to use a compiler that uses the *same* C runtime as the compiler that built perl - which, for ActivePerl, means that you use either MSVC++ 6.0 or MinGW. With ActivePerl-5.6.1, you'll need to install ExtUtils-FakeConfig in order to use MinGW - with recent builds of ActivePerl 5.8 and 5.10 you won't need EU::FC.
Cheers,
Rob