I am using Wndows 7 Starter on a Toshiba NB510. I experienced a problem with the machine, when I foolishly (but unintentionally) made all folders hidden and then couldn't find anything. I managed to reverse this and now all other programs appear to work properly except Firefox and Thunderbird. When attempting to run either, an error message comes up saying "Thuderbiird (or Firefox) is already running, but not responding The old Thunderbird process must be closed to open a new window" but on clicking "Close Thunderbird" another box comes up saying "Your Thunderbird profile cannot be loaded. It may be missing or inaccessible." Uninstalling and re-installing does not cure the problem. Many thanks.