Recently one of my senior colleague was faced with a problem of launching executables from Web Services hosted in IIS. Following is the problem he was faced with (as is email),

“I am working on a dotNet web service that needs to launch an executable (.exe). I have used System.Diagnostics.Process to launch the process. When I run through VS2005 test environment, web service triggers the executable and its UI is displayed (e.g., launching notepad). But when I deploy the web service under IIS, the web service does launch the process but UI does not appear.

Can someone shed some light on what is happening and suggest a solution to this”

After searching on the internet I found the following solution and it worked fine.

According to Microsoft following are the reasons for this

1.    By default, ASP.NET runs its worker process (Aspnet_wp.exe) with a weak account (the local machine account, which is named ASPNET) which don’t have permission to interact with desktop.
2.    By default, IIS Admin Service won’t allow its application to interact with desktop.

These can be resolved by:

1.    Allowing worker process(ASP.NET) to run in SYSTEM account.
This can be done by editing the machine.config file which is located at (C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG. Open the machine.config and find the ProcessModel tag and add the following attributes to it,

userName=”SYSTEM” password=”AutoGenerate”

2.    Enable IIS Admin Service to interact with desktop. To configure this, follow this steps.

a)    Open Control Panel and follow these steps:
For Windows NT: click Services.

For Windows 2000, Windows XP, and .NET Server: click Administrative Tools, and then click Services.
b)    Double-click IIS Admin Service.

c)     On the Log On tab, select the Allow Service to Interact with Desktop check box.

d)    Stop and restart the IIS Admin Service.

3.    Sometimes ASP.NET account does not have enough privileges to access certain WMI namespaces. So to resolve this do the following

a)    Open the Computer Management Microsoft Management Console (MMC) snap-in.
b)    Expand Services and Applications, and then select WMI Control.
c)    Right-click WMI Control, and then click Properties.
d)    In the WMI Control Properties dialog box, click the Security tab.
e)    Expand Root, select CIMV2, and then click Security.
f)    In the Security dialog box, click Advanced.
g)    In the Access Control Settings dialog box, click Add. Select localMachineName\ASPNET, and then click OK.
h)    In the Permission Entry dialog box, make sure that Apply Onto is set to This namespace and subnamespaces.
i)    Make sure that the Allow ‘Enable Account’ and Allow ‘Remote Enable’ check boxes are selected.
j)    Click OK in each dialog box until you return to the WMI Control Properties dialog box.
k)    Repeat steps 5 through 10 for other WMI namespaces that your application will access.
l)    Restart IIS. To do this, run IISRESET from the command line.

Information obtained from:

http://support.microsoft.com/default.aspx?scid=kb;en-us;317012
http://support.microsoft.com/kb/555134

Regards,