Important:
If you have a updatet, updatet, updatet... PoE, play WM 2 until the first town in WM 2. Otherwise the savegames are korrupt with a clean installation.

Clean installation needs only al files from:

PoE 3.00(GOG 13)
WM 1 3.00(GOG 13)
WM 2 3.00(GOG 13)
Pre-Order Bonus Item and Pet
No Patches.

Have fun!