Since there are numerous causes, try something as a test. Install Chrome and what happens with Chrome?
As to the usual, it is too often malware. Grif writes about tools to scan and mitigate malware at link to follow.
I am having facing the issue with internet explorer version 8 in windows xp professional sp3 .
When I clicked on IE on the desktop at a time multiple IE's like 10 to 15 IE's are opening .
Please provide me the solution asap.