I can not use Linux, I have to stay compatible

Whether it is you do not dare using another Operating System or you are not allowed to use another System or you require MS Windows for commercial software. There are lots of Open Source applications for the Win32 Systems.

• Mozilla Firefox, a standards compliant web browser which unlike Internet Explorer offers tabbed browsing making it perfect for h2g2.
  
  [Win32, Linux, MacOS X, Solaris, netBSD]
  
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  OpenOffice.org, a very nice Office type package which once I figured out how to install the 'British English' dictionaries & thesaurus does pretty much everything I would expect from an office package.
  
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  The Gimp (version 2.0), don't laugh despite its name this is a very good graphics editing programme.
  
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  Gaim, an instant messaging programme that supports a number of protocols (Aim, ICQ, MSN, Jabber, IRC plus a few others). I really like this as unlike other multi-protocol IM programmes (e.g the free version of Trillion) it has a spell checker