Wubi Installation Problem: Wubi Process Quits

I've been longing to install an Ubuntu for my PC. Recently, I looked up to my installers' folder in my harddisk and found this wubi installer and the ISO. So I started it. But the process never actually run.
I opened the task manager. For one second or so, the wubi.exe was there. But it quits and did nothing.
Thereafter, I found a forum asking for a solution for the same problem (http://askubuntu.com/questions/40531/wubi-exe-wont-start).
Fyi, my configuration is: windows 7 64-bit with administrative rights.

And so I did exactly what he told.

1. Right click on Computer > Properties > Advanced System Settings.
2. On the advanced tab, choose environment variables.
3. On the fields environment variables, find one that says 'PYTHONPATH' on the variable name (left side).
4. delete it.

If you by any chance, are willing to use the variable later, you can just temporarily delete it, and SHAZAM, wubi.exe is working.