Note : This solution regarding to audio works after installing batch file KB835221. - It's a solution to most Compaq Laptop.
Download the CQAudioSolution
Inside the RAR file there is an audio patch and devcon patch file. Devcon file will solve issue with KB835221 (missing PnP function id). Follow the procedure below.
1) You must install two patches first from Microsoft: KB835221 (UAA version 1.0) and then KB888111 (UAA update version 1.0a)
2) Install the IDT HD Audio Driver.
3) Extract CQAudioSolution.rar
4) Extract devcon.exe self-extracter from Devcon folder extracted in step 3.
5) Copy devcon.exe from extracted folder in step 4 to C:\WINDOWS\SYSTEM32.
6) Run Audio path from extracted Audio Path folder in step 3.
7) Restart your laptop.
8) The sound should be up and running after your restart.
9) However, in Device Manager, there is a exclamation icon on "Audio Device on High Definition Audio Bus". This is installed by KB835221 patch. Just ignore it. The CQAudioSolution will make sure that there is no more issue with missing IDT HD Audio when restarting after installing the IDT HD Audio driver.