Do pc games work that are from different countries

I believe all PC DVD drives are compatible with all region CD/DVD's. As you may know, they is PAL and NTSC, PAL is more popular in different countries. Look here:
PAL
Afghanistan
Algeria
Argentina (N)
Austria
Australia
Bangladesh
Belgium
Brazil (M)
China
Denmark
Finland
Germany
Hong Kong
Iceland
India
Indonesia
Iraq
Ireland
Israel
Italy
Jordan
Kenya
Kuwait
Liberia
Malaysia
Netherlands
Nigeria
Norway
New Guinea
Pakistan
Singapore
South Africa
South W. Africa
Sudan
Sweden
Switzerland
Thailand
Turkey
Uganda
United Kingdom
United Arab Emirates
Yugoslavia
Zambia


NTSC
Canada
Chile
Costa Rica
Cuba
Dominican Republic
Ecuador
Japan
Mexico
Nicaragua
Panama
Peru
Philippines
Puerto Rico
South Korea
Taiwan
U.S.A.