After countless trial and errors, I've successfully installed a functional webmin on windows 7 and a windows 2003 server. I presume this method would work for most Window OSes. Here's a detailed tutorial.
Required Files: ActivePerl 5.16 x86
These can be easily found on google.
1. Unzip webmin-1.610.zip
2. Put extracted webmin folder in C:\
3. Put process.exe in C:\webmin
4. Append C:\webmin in Environment Variable PATH change.
5. Open CMD terminal, type "cd C:\webmin"
6. type "ppm install win32-daemon"
7. Create new folders named etc and temp in your c directory. i.e c:\etc, c:\temp
8. open new CMD terminal, type "cd c:\webmin"
9. type "perl setup.pl"
10. For config, type "c:\etc"
11. For logs, type "c:\temp"
12. type 10000 for port
13. select no ssi,
14. select yes start at boot time
15. create a user/password
At the end of the installation, the terminal will show you the address for you to go on webmin browser. Congratulations!
I installed webmin on Win 8.1, it worked for me. Needed to run cmd as Administrator and also when asked for the log directory I entered "c:\\temp" instead of "c:\temp"