I have every sympathy with this problem.
My version of the problem is this.
For ease of exchange of files, as in the Open University UK, I save all files as .RTF.
If I click on a file ending .RTF or .rtf this error message pops up.
If I start by opening the word processor first and then open the file - no porblem. This applies to Star Office and to WinWordXP.
If I change the ending to .doc, as Star Office is the programme I use most, it opens without any problem.
The problem that then arises is that I also transfer files to my palm top Jornada which runs Pocket Word. When it imports .doc files it converts them to .pwd, Pocket Word, files. These cannot be read when transferred back.
So I want my .rtf files to open properly. My laptop came with XPPro installed and all the programmes I use are compatible with this system.
It appears to have a bug which gives this error message built in.
So whats the answer?