Hello.
After adding the BIN directory to the PATH variable in the system variables 
list, pgAdmin now shows the Backup and Restore items.
Thanks everybody for your help.
Hélder M. Vieira
>> I've just removed PostgreSQL 8.2 Beta 3 and installed the 8.2 RC1 package 
>> in a Windows 2000 Pro machine.
>> With pgAdmin, I created a database and tried to restore a backup.
>> At this point I noticed that, in the context-sensitive menu over the 
>> database name in the Object Browser, the Backup and Restore items were 
>> missing.
>> In the Tools menu, both the Backup and Restore items were grayed.
>> The pgAdmin build included in the PostgreSQL 8.2 Beta 3 package worked 
>> normaly.
>> Both pgAdmin, pg_dump and pg_restore are in the bin directory.
>>
>> Could someone please give me a hand ?
>
> http://www.pgadmin.org/archives/pgadmin-support/2006-11/msg00168.php