Recently I accidentally downloaded some adware called
VX2.BetterInternet onto my Windows 2003 server which I use for
development.  After getting rid of the adware, I discovered that it
had killed my Visual Studio debugger.  I was getting a message not
found in the http://www.gotdotnet.com/team/csharp/learn/whitepapers/howtosolvedebuggerproblems.doc
document.  When trying to start a web application with debugging (F5),
Visual Studio would return this message:

"Error while trying to run project:  Unable to start debugging on the
web server.  You do not have privileges to debug the web server
process.  Contact an Administrator to get the debug privileges on the
server.  You may also want to refer to the ASP.NET and ATL Server
debugging topic in the online documentation."

Research and comparing my server to other developers' in my office
utlimately revealed that the local security policy settings had
changed.  Here is what I had to do to fix the problem.

From Administrative Tools, open the Local Security Policy snap-in for
Microsoft Management Console.  Open the Local Policies node and then
the User Rights Assignment node.  Open the properties of the "Debug
Programs" policy.  On my server, the adware removed all security
settings for this policy.  It should have the Administrators group and
the VUSR_yourcomputername user in the list.  If not, add them and save
the properties.  Then close the Microsoft Management Console.

If you had to modify the security policy above, open a command prompt
window.  (Assuming that the system32 directory is part of the path
environment variable, you should not need to change directories.)
Update the group policy by typing the following command:
   gpupdate /force

For Windows 2000 users, there is a different command set.  See
http://support.microsoft.com/default.aspx?id=227448

After updating the group policy, I had to reboot the server in order
for the change to take effect.

I hope I can make someone else's life a little easier with this
information.