Why I get this connection error when I try to start TOR as a non NT Service?

[Lanthanaël]

I think the subject says its all. If I try to start TOR normaly it 
dosn't work just as a NT service, if I check the box, run as NT Service 
everything is well and TOR works, but if I uncheck the box run as NT 
Service TOR stops working. Why is this in that way?
Here my error log.

Mär 10 14:27:57.140 [Warnung] Could not bind to 127.0.0.1:9050: 
Permission denied [WSAEACCES ]
Mär 10 14:27:57.156 [Warnung] Failed to parse/validate config: Failed to 
bind one of the listener ports.
Mär 10 14:27:57.156 [Fehler] Reading config failed--see warnings above.

Every system service is configured propably the firewll and the virus 
scanner are also configured to let TOR working.
What is this thingy permission denied [WSAEACCES]? And what the hell is 
this [WSAEACCES]?

My System: Windows Server 2003 Enterprise x64 Edition R2

I searched the web but can't find an answer. So, how do I solve this 
problem, because I don't want tu run TOR as an system service?

Thenks, Lanthanaël