I have a 5-year-old Acer Aspire 4520. Until a month back it was working beautifully on Windows 7 32bit. But then out of the blue, the sound stopped working. I've tried reinstalling the OS 3-4 times. The sound came back a couple of times, but it stopped working after a reboot. Even after installing the sound drivers, I don't see any entry in the Playback tab of the Sound applet in Control Panel.
I see a High Definition Audio Controller entry in Device Manager. I disabled and uninstalled it, but Windows reinstalls it automatically. I'll share specific hardware details if anybody here needs to know. The processor is "AMD Athlon(tm) 64 X2 Dual-Core Processor TK-55".
Any help would be appreciated.