Cara Mengatasi Web Asp.net yang tidak bisa di panggil dengan localhost maupun ip

Halo Para Master,

Saya mau tanya, kebetulan saya newbie di dunia programmer apalagi asp, saya mengalami kendala, saya ingin membuat web server sendiri di rumah, kebetulan script website itu bekas dipakai oleh kantor dan saya sudah modifikasi, tapi ketika saya panggil dengan localhost maupun ip selalu tidak bisa, script tersebut hanya berjalan jika di akses dari router... Mohon pencerahannya ya para master

berikut pesan erro kala di panggil menggunakan localhost / ip

Server Error in '/' Application.

'http://192.168.100.100:81/default.aspx' is not a valid virtual path.

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.Web.HttpException: 'http://192.168.100.100:81/default.aspx' is not a valid virtual path.

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:

[HttpException (0x80004005): 'http://192.168.100.100:81/default.aspx' is not a valid virtual path.] System.Web.VirtualPath.Create(String virtualPath, VirtualPathOptions options) +8851275 System.Web.HttpContext.RewritePath(String path, Boolean rebaseClientPath) +116 System.Web.HttpContext.RewritePath(String path) +6 MyHandler.OnBeginRequest(Object sender, EventArgs e) +13591 System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +68 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75