Actually solve the "HTTP 500 internal server error" of IIS server

Today's classmate's computer IIS server suddenly has a problem, let me help, I looked at it, his system is Windows XP SP2, IIS version is 5.1, the fault phenomenon is to enter http in the browser address bar: After //127.0.0.1, the "HTTP 500 Internal Server Error" prompt appears.
After checking the reason of "HTTP 500 internal server error" on the Internet, I tried a lot of methods on the Internet, but it didn't work. Some netizens even came to the conclusion that "only reinstalling the system can solve the problem" I after many experiments, and finally come to a real solution, the following way:

1. run -> cmd-> enter net start msdtc, there was an error message that the service can not be started. 2. Delete the key in the registry:
HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Services\\MSDTC
HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\MSDTC
HKEY_CLASSES_ROOT\\CID 3. Stop the MSDTC service: net stop msdtc 4. Uninstall MSDTC Service: msdtc -uninstall
5. Reinstall MSDTC service: msdtc -install 6. Restart the computer
7. Start the service: net start msdtc
8. Reset the IWAM account password of IIS. (in the user management in computer management), as shown below:

9. Synchronize the password of IWAM_MYSERVER in IIS metabase, in CMD: c:\\inetput\\adminscripts>adsutil set w3svc/wamuserpass "yourpassword"< BR> 10. Synchronize the IWAM_MYSERVER password used by the COM+ application. In CMD: c:\\inetput\\adminscripts>cscript synciwam.vbs -v
11. In the browser address bar, type: http://127.0.0.1 It can be found that IIS is working normally at this time, see the following figure:
Attached: Online description of IWAM account: IWAM account is a built-in account automatically created when IIS5 is installed, mainly used for startup process. Application Internet Information Service. The name of the IWAM account will vary depending on the name of each computer's NETBIOS. The common format is IWAM_MACHINE, which consists of the "IWAM" prefix, the connection line "_" plus the NETBIOS name of the computer. The NETBIOS name of my computer is MYSERVER, so the name of the IWAM account on my computer is IWAM_MYSERVER, which is very similar to the IIS anonymous account ISUR_MACHINE.

IWAM account established after the Active Directory, IIS metabase database and COM + applications using the three parties, account password three were saved by the operating system responsible for this three-way synchronization IWAM saved passwords. According to common sense, we can rest assured that the work done by the operating system can be assured that there is no need to worry about errors, but I don’t know if it is a BUG or any other reason. The password synchronization work of the IWAM account sometimes fails, and the password used by the three-party IWAM account is not uniform. When the IIS or COM+ application logs in to the system with the wrong IWAM password, when the IIS Out-Of-Process Pooled Applications is started, the system will reject the request due to a password error, causing the IIS Out-Of-Process Pooled Applications to fail to start, that is, We can't see the server {3D14228D-FBE1-11D0-995D-00C04FD919C1} in the ID10004 error event (here {3D14228D-FBE1-11D0-995D-00C04FD919C1} is the KEY of IIS Out-Of-Process Pooled Applications) Can't transfer to IIS5 application, HTTP 500 internal error is generated.