I have I think a better way, though is similar to the one Redman told you.
I will post all the steps so you don't get confused:
1) Install PES4
2) Make a copy of the installation directory and call the folder the wayyou want it (i.e. Pro Evolution Soccer 4 Wolf)
3) Then, find the registry file HKEY LOCAL MACHINE/SOFTWARE/KONAMI/ and in the Pro Evolution Soccer folder of the registry, there must be a Regcode called "instaldir". (until now, the same solution Redman told).
4) What you do now is to create another Value called instaldir1 (just the same as the one that is already there). You will now have two strings, one called instaldir and another called instaldir1. (you can also make a copy of instaldir and rename it instaldir1).
5) What you do next is to open the value, and change the string there. In "instaldir" it should point to "C
Program Files\Konami\Pro Evolution Soccer 4\", and what you have to do is to edit that value in "instaldir1" key. Instead of that you point to the installation directory where you have the patched version (in our example "C
Program Files\Konami\Pro Evolution Soccer 4 Wolf".
6) And now the final touch. You hexedit the .exe file PES4.exe. You must make a search for "instaldir". Once you find it you replace that value with "instaldir1" so the .exe points to the directory you chose.
In this way you don't have to change the registry values every time you want to play with different patches.
Hope it helps.
Let me know if you need further help.
Manuel