Problem Re-Installing RS

[Rafa®]

My report server failed, and the ReportServer database was stored on a
another...
When we got the server up again, I backup the "ReportServer" Database,
dropped it, re-installed Reporting Services, installed SP1, and then Restored
the "ReportServer" Database Backup...
After that, when I try to open any report on the server, I get the following
error:
- The report server installation is not initialized. Check the documentation
for more information. (rsReportServerNotActivated) Get Online Help
-2147159550

So, I got the RS Help, and knew about the "rsactivate" tool...
When trying to run the tool, to activate my server and get all working back
again, I get the following errors:
- running: "rsactivate -m [myRemoteServerAddress]"
Error: "Failure obtaining information form remote WMI provider: Unable to
find Reporting Services WMI namespace on SQL01. Reporting Services may not be
installed."
- running: "rsactivate -m 127.0.0.1 (local machine)"
Error: "Failure initializing remote NT Service: The local NT Service is
not activated."

I need to up this server again, as soon as possible...
According to what I read in the help, the only thing I need to do, to
accomplish this from where I am, is to activate the server...
Can someone help me to know why I got these errors running rsacitvate?
Thanks...
Rafa®