How many computer users are there in respectively USA and Western Europe?

I’m not sure about computer users, but if you assume that most computer users are Internet users, there are 212 million in the US and 322 million in Europe.

Thanks, about what I was asking about. Any sources, statistics, etc?

If you click on the links above, you’ll see the sources for the US number is Nielsen//NetRatings. The European usage numbers come from various sources, including Nielsen//NetRatings, ITU, C-I-A, and local NICs.