chennaiite,
I assume you have RTFM'd regarding Net::Telnet and windows machines. The author didn't think too highly of Window's telnet. OTOH, the module has been touched since 2002 so perhaps it is much less of a problem since it was written. Using Super Search and looking for Net::Telnet and windows, it seems as though people are having a wide range of problems. Here are a couple of the prompts I saw used with apparent success:

Prompt => '/>/',

Prompt => '/C:\\\\>.*$/');
[download]

Hope this helps!