Sound is being disabled after reinstalling windows xp of my Laptop

Acer travelmate 530
Model # BY27
Operating system Windows XP wth servicepack 3


After being reinstalled windows xp the sound of my laptop has been disabled. The icon of sound in the right bottom of the screen has been gone. And now I got different sound errors, sometimes when I go to:- 1. start/ all programs/accessries/entertainment/ volume control and then click I got the error that "there is no active mixer device avaiable. 2. On control panel when I click on sound and audio devices I found all the options related to sound are being disabled. 3. I also checked out the harware section on MY Comuter, the sounds drivers are there but something goes wrong with respect to that.
I have already downloaded audio, vga, and someother drivers from ( and installed them but the problem is still there that is the sound is disabled.
I would really appreciate on this forum if I can get the solution from someone with respect to that sound problem I am facing.
I can't want to open my laptop's harware because I cant do that.