I realize this thread is 9 years old but, since someone necro'd it, I thought I'd add a bit to it.
To be honest, I wouldn't bother with "SQL Server Active Directory Helper". It was discontinued in SQL Server 2012.
The question is, what are you trying to do with it? There are a lot of ways to interrogate Active Directory from SQL Server.
To be equally honest if you're still on Windows 2003 and/or SQL Server 2005, you're using a product that was introduced in 2003 (Windows) and 2005 (SQL Server) Windows Server 2003 has some pretty nasty security holes compared to the latest and greatest (which also has some security holes... it seems like it always does). SQL Server 2005 is also 14 years old, has some security issues, and the newer versions have a lot of great new functionality.
My recommendation would be to develop a plan and upgrade as soon as possible. If you're using 3rd party software that cannot withstand such upgrades, I'd make sure the machine that's on were as isolated as possible from everything else.