Error:"Requested registry access is not allowed" while invoking web service method

[swatitalati]

Hello

when i invoke a method of web service i m getting error like Server was unable to process request. --> Requested registry access is not allowed.

syntex for invoking method is as below
object[] results = this.Invoke("authenticate", new object[] {
strUserName,
strPassword});

Pls help me to figure out this problem

Thanking You in advance
Swati