Currently I am using Ubuntu 11.10 and I have tried installing Windows games with "PlayOnLinux" but all the games I tried to install it displays an error (it says that the program should be closed). Please what can i do?.
Desura is a software that allows to play games on Ubuntu, but most games are not free. You can find here installation instructions:
I faced the same problem (Excel, not games) and finally installed VMWare Player. Just install the flavor of Windows you like and after that install the game you want to play.
one of possible solutions is to install wine.
for me it was my way to play Counter Strike 1.6 (Ubuntu 16.04)