Why when I click Security on Web Site Administration Tool, shows up the 
error:

"There is a problem with your selected data store. This can be caused by an 
invalid server name or credentials, or by insufficient permission. It can 
also be caused by the role manager feature not being enabled. Click the 
button below to be redirected to a page where you can choose a new data 
store.

The following message may help in diagnosing the problem: An error occurred 
during the execution of the SQL file 'InstallCommon.sql'. The SQL error 
number is 1802 and the SqlException message is: CREATE DATABASE failed. Some 
file names listed could not be created. Check related errors. Cannot create 
file 'C:\DOCUMENTS AND SETTINGS\SUPORTE\MEUS DOCUMENTOS\VISUAL STUDIO 
2005\WEBSITES\WEBSITE6\APP_DATA\ASPNETDB_TMP.MDF' because it already exists. 
Change the file path or the file name, and retry the operation. Creating the 
ASPNETDB_9a00681a89b84fbe9b629ceaadb14857 database..."

Thanks in advance!