I have installed windows7 pro 32bit, . I can play music and hear it. I cannot hear anything with bbc iplayer or incredimail even thouth the settings are on. I only hear windows sounds on startup and closing down, no other time. I have a dell optiplex 170L, 1.5gb ram 2.8ghz procesor, and a soundmax IDA which show microphone and speakers ticked. But shows sounds tab but on test no sound is heard. Any advice?

The problem is you have a relatively old system and there is absolutely no Windows 7 support from Dell for your system. Microsoft does not write nay drivers or utlility software for Dell products. That is the sole resonsibility of Dell. Your best bet is to try the Dell Community Support forums and see if there are other with your hardware. The software you are having problems with may not be compatible with Windows 7 either. You would need to contact the publisher to check on that issue. Go to http://en.community.dell.com/support-forums/desktop/default.aspx and search for your OptiPlex 170L.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.