Hi you must complete uninstall your sl and then reinstall again.
How to complete uninstal sl from your pc.at Windows O.S
1-open a folder (any folder) at the top bar select folder options check the option show hidden files/folders
2- run the sl uninstaler this can be done by windows uninstaler or at programs menu at sl uninstal shortcut
3-after complete uninstal go to c: select documents and settings open the administrator folder(the one with the same name of the pc) select the folder named application data,open it and them delete the second life folder
4- return now to documents and settings ,select the folder local definitions open it select the folder application data open it and delete the folder called second life
5-open a run window type there "regedit" you will be show a registry window select HKEY_CURRENT_USER open it
select now the folder called software open it find a folder called Trolltech delete it
6- now at the same inside the registry window select HKEY_LOCAL_MACHINE open it select now the folder called software open it find a folder called Trolltech if is there delete it if you can't find it,no problem is because is not there just close the registry window and now sl is complete removed from your computer
7-restart your computer
8- install sl again
if you dont know how to do this IM me i help you