R help - Mar 2008 - Error: file association for 'doc\html\index.html' not available or invalid

Today HTML help stopped working. The menu command "Help > Html
help" usually
brings up my default web browser (Opera 9.26), but now R gives the error
Error: file association for 'doc\html\index.html' not available or
invalid
If I try the same menu command a second time, R crashes with the message

The instruction at "0x7c9106c3" referenced memory at
"0x7c9f4302". The memory
could not be "written".

The same problem occurs when calling help from the command line, e.g. with
 ?license

I'm running R 2.6.2 on Windows XP SP2. Googling for the error turns up
nothing,
and I have no idea where to look for further diagnosis. I have uninstalled, 
deleted the R package directories, and checked the registry for metions of 
"\R\", but the problem remains. I can't think of any unusual
changes I made
before this problem arose.

Any help would be appreciated.

Best regards,
Jon Olav Vik

On Fri, 7 Mar 2008, Jon Olav Vik wrote:
> Today HTML help stopped working. The menu command "Help > Html
help" usually
> brings up my default web browser (Opera 9.26), but now R gives the error
> Error: file association for 'doc\html\index.html' not available or
invalid
> If I try the same menu command a second time, R crashes with the message
>
> The instruction at "0x7c9106c3" referenced memory at
"0x7c9f4302". The memory
> could not be "written".
>
> The same problem occurs when calling help from the command line, e.g. with
> ?license
>
> I'm running R 2.6.2 on Windows XP SP2. Googling for the error turns up
nothing,
> and I have no idea where to look for further diagnosis. I have uninstalled,
> deleted the R package directories, and checked the registry for metions of
> "\R\", but the problem remains. I can't think of any unusual
changes I made
> before this problem arose.
Try re-setting the file association for .html files -- it looks as if it 
has been corrupted (not by R).

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595