This might not be much of a help, but try to explain it further?

If I understand you correctly, your problem is that other programs takes
focus (switching the view to them)? But without closing whatever program you
where using. Is it different programs that do this, or the same one all the
time?

However I don't know how to fix this. Maybe you got some malware in your
system? Try scanning with ad-aware, spybot S&D and an anti-virus.

Ad-aware: http://www.lavasoftusa.com/products/ad-aware_se_personal.php
Spybot: http://www.safer-networking.org/en/home/index.html

Other tidbits, I'd recomend Spywareblaster and Windows Media Player
Scripting Fix: http://www.javacoolsoftware.com/downloads.html

AVG antivirus: http://free.grisoft.com/freeweb.php/doc/2/

Or maybe the problem is completely different... maybe you have a wireless
keyboard, and your neighbour has one too.. but then you'd have trouble
writing, so I guess not:)

-Gawron