in reply to Problem on installing DBD-Oracle

you're trying to build module from source but you do not have compiler installed (your config thinks you should use MSVC++)

You probably need to obtain binaries from repository with PPM such as http://aspn.activestate.com/ASPN/Modules?module_name=D&order=name&query_start=106 (but it seems to be for perl5.6.1 perl, you need to search deeper than me:)

addition: DBD-Oracle seems to be mentioned at http://aspn.activestate.com/ASPN/Downloads/ActivePerl/PPM/Repository, so your chances to get binaries are very high!