<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <directoryBrowse enabled="true" />
        <defaultDocument enabled="true">
            <files>
                <clear />
                <add value="index.html" />
                           </files>
        </defaultDocument>
        <httpErrors errorMode="Detailed" />
        <asp scriptErrorSentToBrowser="true" />
        <handlers accessPolicy="Read, Execute, Script">
            <add name="Perl" path="*.pl" verb="*" modules="CgiModule" 
+scriptProcessor="D:\Strawberry_Perl\perl\bin\perl.exe &quot;%s&quot; 
+%s" resourceType="Unspecified" />
        </handlers>
    </system.webServer>
    <system.web>
        <customErrors defaultRedirect="http://mypage.com:9900/inc3/" m
+ode="On" />
    </system.web>
    </configuration>
[download]

"I think so"

Since you've been asked the question, find out the answer :)

"what you mean by impersonate user?"

As above, ensure you're looking at the 'website' settings, under the IIS section (starting 'ASP', 'authentication' ...) you'll see 'CGI'. That's where to find impersonate user. What do the IIS log files say caused the 500 error?

yes cgi is added, simple scripts would also work fine.

 Security: taking Identity of user[createProcessAsUser] = true
to use new Console = false;
[download]

The log file doesn't say much:

 
#Software: Microsoft Internet Information Services 7.5
#Version: 1.0
#Date: 2017-10-23 09:46:56
#Fields: date time s-sitename s-ip cs-method cs-uri-stem cs-uri-query 
+s-port cs-username  cs(User-Agent) sc-status sc-substatus sc-win32-st
+atus
2017-10-23 09:46:56 W3SVC14 ip GET myScript.pl - 9900 -  Mozilla/5.0+(
+Windows+NT+6.1;+WOW64;+rv:52.0)+Gecko/20100101+Firefox/52.0 200 0 0
2017-10-23 09:47:22 W3SVC14 ip GET myScript.pl - 9900 -  Mozilla/5.0+(
+Windows+NT+6.1;+WOW64;+rv:52.0)+Gecko/20100101+Firefox/52.0 200 0 0
[download]