1. no audio device, if you sound card is integrated , first to CMOS inside look at sound card was disabled or not, then again consider driven of problem,
in device management Manager in look at is has yellow of question mark or is laments,, some words on double-click the device (into driven CD), click Update driven program, by prompted update can (don't said you does not yo).
also directly can be placed in the driver CD to install the driver, after installing your reboot should resolve the issue.
2, and if sound card is independent, first look card gold finger whether oxidation, as found gold finger gloss Dim found block rubber wipe to oxidation layer, again see PCI slot within whether has product dust, if has words with rubber blowing blowing clean dust, again with new of Yuan folding up to slot inside wipe about, then will sound card
insert PCI slot within, must to plug tight, also no on for a slot try try. Determine Board connection when there is no problem, follow the steps to install drivers, in case of hardware damage alone will solve the problem.