hi, im navaz, having a problem. working on a project having a user like mossapp,mossadmin,123users,456users, when i login as 123users and 456users, i have i logged in. where i logged as mossapp,mossadmin. its shows erroe below. please could any one help or suggest to me how to overcome,, before that i googled this error i find the solution to reset the app pool, i tried that but not work.. thanks in advance. ha Server Error in '/' Application. Illegal operation attempted on a registry key that has been marked for deletion. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Runtime.InteropServices.COMException: Illegal operation attempted on a registry key that has been marked for deletion. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: [COMException (0x800703fa): Illegal operation attempted on a registry key that has been marked for deletion. ] System.DirectoryServices.PropertyValueCollection.PopulateList() +547615 System.DirectoryServices.PropertyValueCollection..ctor(DirectoryEntry entry, String propertyName) +97 System.DirectoryServices.PropertyCollection.get_Item(String propertyName) +172 System.DirectoryServices.AccountManagement.ADUtils.RetriveWkDn(DirectoryEntry deBase, String defaultNamingContext, String serverName, Byte[] wellKnownContainerGuid) +64 System.DirectoryServices.AccountManagement.ADStoreCtx.GetGroupsMemberOf(Principal foreignPrincipal, StoreCtx foreignContext) +644 [PrincipalOperationException: Illegal operation attempted on a registry key that has been marked for deletion. ] System.DirectoryServices.AccountManagement.ADStoreCtx.GetGroupsMemberOf(Principal foreignPrincipal, StoreCtx foreignContext) +2188 System.DirectoryServices.AccountManagement.Principal.GetGroups(PrincipalContext contextToQuery) +20 TCSCustomMOSSAuthProvider.TCSCustomMembershipProvider.SetSession(String Uname, String[] ADstr) +6641 TCSCustomMOSSAuthProvider.TCSCustomMembershipProvider.ValidateUser(String username, String password) +152 System.Web.UI.WebControls.Login.AuthenticateUsingMembershipProvider(AuthenticateEventArgs e) +75 System.Web.UI.WebControls.Login.AttemptLogin() +152 System.Web.UI.WebControls.Login.OnBubbleEvent(Object source, EventArgs e) +124 System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +70 System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +29 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2981

Hi, Thanks to share your post. For the issue, i think it is in the support center in Microsoft: http://support.microsoft.com/kb/829888. Hope this could help you! Leo

I know this is a bit old and you probably have already solved it, but its registry errors. CCleaner (free to download) fixed it for me, so may fix for you also. Good Luck!