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#11
The jack could be the problem. On many older PC's (and this is an older PC that either came with XP or possibly 32 bit Vista) there is an extra contact in the jack that is opened when a headphone plug is inserted and closed when the headphone plug is removed. If that contact is not closing it could think there is still a headphone plugged in.
New/newer PC's have jack sensing and don't need the extra contact.
I don't think is a driver problem as the ear phone works. I agree with Oscer on post 9.
When you insert a ear phone, there is a switch that disconnect the speakers.
I've seen a laptop that the user used to twist the ear phone jack to take it out. It damaged the switch and the speakers didn't work any more.
thanks guys for your valuable input