Your database is read-only, or owned by a different user
on your machine. In some circumstances, the folder where
ThumbsPlus keeps the database gets marked by Windows or some
other application as unshareable.
If you need ThumbsPlus only for a single login, you can
uninstall and reinstall ThumbsPlus 8, and select the option
for each user to have separate databases. This will
place the database in your user folders. (This is usually C:\Users\<name>\AppData\Roaming on
Vista or Windows 7).
Alternately, if you're familiar with
Windows security, you
this problem by making the common folder and and its
contents writable by Everyone or Authenticated
On English version of Windows, the common folder is usually
or C:\Documents and Settings\All Users\Application
Data\ThumbsPlus (2000, XP).
A third option is to create a new database in a different
location (Database - New...). However,
you should not create a database in the root of the C:\
drive, or in C:\Program Files... or C:\Program Files (x86)...,
as these are protected by Windows.
The Vista and Windows 7 page may be helpful as well.