Thanks GX1-Man and 2k-Dummy for your responses. Taking the second first, I have no "Update Driver" in my Win98SE Device Manager. Under Sound,Video and Game Controllers, an entry confirms the installation of the AC97 Driver and there is also an entry-"Unknown Device"- which has a yellow 0 beside it. It may not be relevant, but a PCI Universal Serial Bus entry has a yellow ? and an O beside it. To answer GX1-Man, I was advised to get the AC97 by someone who builds computers and, although I'm not positive about it, I think it is the same as the driver I had originally.
Could you please explain your suggestion to delete all sound drivers, which sounds rather a drastic "solution" to me ? (But what do I know.!!) Cheers, Alpha.