Port win7 80 is occupied by System

Port 80 of win7 is occupied by the system process by default.
The following method can be used to solve the problem that the system process occupies port 80:
Open regedit:
Locate HKEY_LOCAL_MACHINE/system/CurrentControlSet/services/HTTP
Find a DWORD value, and change it to 0

Restart the computer. The system process will not occupy port 80.

========================================================== ====

After Windows 7 is installed, Apache always fails to be started. Check port 80, which is occupied by PID = 4. Open the task manager, we found that the PID = 4 process is actually a system process!

Try to terminate this process and the result is a blue screen.

Solution Process:

After checking on the Internet for a long time, I found the following solutions:

(Source URL: http://www.cameroncooke.com/2009/01/25/windows-7-uses-port-80-and-makes-it-impossible-to-install-apache-solution/comment-page-1/#comments
)

Original article:

I work on HTTP. sys technology at Microsoft and somebody sent me
Link to this blog. I am a bit surprised by this behavior you are seeing
On windows7 beta and with some help from you, I will like to find out
The root cause of this issue so that we can take the appropriate action
If needed.
You are right, HTTP. sys uses port 80. It is the driver
Component for httpapi, the server HTTP stack (you can find more info on
This technology at http://msdn.microsoft.com/en-us/library/aa364434 (vs.85). aspx
). In your case, some application is running which is using HTTP. sys
Listen on port 80. This is preventing Apache from using port 80. We
Offer a mechanic for applications to help control port sharing but I'll
Need to look into the specific application that's causing you this
Conflict. If you can give us the output of following command "netsh HTTP
Show servicestate ", then it will allow me to find out which application
Is using HTTP. SYS. Since you have disabled HTTP. sys, please follow
These steps listed below before running the command:
1. SC config HTTP start = demand
2. Reboot
3. Run the command (netsh HTTP show servicestate) as Administrator

After you have run this command, you can disable HTTP. sys as follows:
1. net stop HTTP
2. SC config HTTP start = disabled

Please let me know if you face any issues in the process.

Thanks,
Niranjan