[R] Fatal error: invalid home drive

[Jonathan Williams]

Dear R-helpers,

I have just installed R2.0.0 onto my machine which already had R1.9.1
present.
I then tried to add to R2.0.0 a library called GLMM written by James McBroom
for R1.6.0. Unfortunately, R2.0.0 does not recognise the library, even
though
R1.9.1 does. This is not because I have used the wrong case in the call to
the
library:
> library('GLMM')
> "Error in library("GLMM") : 'GLMM' is not a valid package -- installed <
2.0.0?"

So, I was hoping to revert to using GLMM in R1.9.1. BUT, when I now try to
load
R1.9.1, I receive "Fatal error: invalid home drive".

Is there any way I can resurrect my R1.9.1, which is still present
physically
on my HDD? I am working with Windows XP on a 2.4GHz desktop with a large
HDD.

Is it now the case that R2.0.0 will only run packages which it has installed
itself, and not those that the user imports from earlier versions of R?

Thanks for your help,

Jonathan Williams