Apparently, your problem is very common seeing how many threads my Bioware forums search brought up.
A solution is here:
http://consumer.installshield.com/kb.asp?id=Q108167
2 more possible solutions (simple ones so you might want to try them first)
http://forums.bioware.com/viewtopic....60698&forum=10
http://forums.bioware.com/viewtopic....68979&forum=10
If not try searching the bioware forums. A search result page is here
Seach results.