You have installed a PPM for Perl 5.12. This cannot work with Perl 5.6.

If you want to help us help you better, you could tell us the error messages you get when compiling Win32::API. That way we can see where it goes wrong for you. Looking at the Changes for 0.75, it seems that at least version 0.75 (again) supports Perl 5.6.

As an aside, in your case, I would really look at upgrading Perl to a more recent version, especially for new development. ActiveState Perl and Strawberry Perl offer recent versions that already include Win32::API.

I didnot install PPM separately. It was inbuilt, when installed perl 5.6.

I just downloaded the win32::API-0.40 version and tried to install using PPM -- ppm intsall Win32-API.ppd.

Can you please let me know the installation steps to install win32-API-0.75 on perl5.6??

I'm sorry, I meant to say "The PPM files you downloaded" were for another version of Perl.

You install Win32::API like you install any other Perl module:

C:\>cpan Win32::API
[download]

or alternatively, download and unpack Win32::API:

C:\> cpan
cpan> look Win32::API
C:\...>perl Makefile.PL
C:\...>perl -V:make
C:\...>dmake
C:\...>dmake test
C:\...>dmake install
[download]

Depending on the output of perl -V:make you might need to use a different program than dmake. Most likely that is nmake.

See A guide to installing modules for Win32 for example.

This has been discussed under your previous posts on this topic. You previously asked for a version prior to 0.41 as you knew it didn't work with Perl 5.6.x, instructions were provided to get v0.20. The author even released a new version of the module, adding 5.6 support and told you about it Re^3: Unable to install win32-API-0.41 module on perl 5.6.1.635. Changes:

2013-01-09  Win32::API v0.75    bulk88
   - Fixed/added, alpha Perl 5.6.2 support has been added, ::API will 
+compile,
     will not crash except for randomly threading_fails.t . Many tests
+ fail due
     to prerequities not being met. 00_API.t should pass on 5.6.2 with
+ zero
     failures wWITHOUT prereqs. Other tests require Math::Int64 and
     Encode::compat.
   - Removed, distropref workaround for ActiveState's PPM system (AS f
+ixed it)
[download]

I suggest you take the time to read the responses you have, install this new build and if you have any problems consider asking a sensible question, not a mixture of your various existing posts and failed attempts. How do I post a question effectively?