Vista to XP audio drivers

Which C700 is it? C700EM?

You can also run SIW (http://www.gtopala.com/) to get the make and model, then paste that into this thread.

I would check the power plan and the advanced section just to be sure nothing has changed there.

Take a look at Control Panel / System and Maintenance/ Power Options/ Change Plan Settings/ Advanced

Crap - wrong thread - sorry.

It's always best to do a screen shot of the Device manager before you wipe the OS.
What is the specific model number. Should be on a sticker underneath your lappy.

Here is an XP driver for the C713 series
ftp://ftp.hp.com/pub/softpaq/sp36001-36500/sp36090.exe

You have this audio: Conexant High-Definition Audio Driver

Since it's High-Definition, you'll need to install the corresponding Microsoft Universal Audio Architecture (UAA) Bus Driver for High Definition Audio driver first.

Try one of these pairs of drivers:

UAA: sp31994

http://h10025.www1.hp.com/ewfrf/wc/genericSoftwareDownloadIndex?softwareitem=ob-45957-1&cc=us&lc=en&dlc=en&dlc=en&lang=en

AND

Conexant: sp32898

http://h10025.www1.hp.com/ewfrf/wc/genericSoftwareDownloadIndex?softwareitem=ob-40639-1&cc=us&lc=en&dlc=en&dlc=en&lang=en

OR

UAA: sp32646

http://h10025.www1.hp.com/ewfrf/wc/genericSoftwareDownloadIndex?softwareitem=ob-45958-1&cc=us&lc=en&dlc=en&dlc=en&lang=en

AND

Conexant: sp35682

http://h10025.www1.hp.com/ewfrf/wc/genericSoftwareDownloadIndex?softwareitem=ob-49193-1&cc=us&lc=en&dlc=en&dlc=en&lang=en

here is more info...

Manufacturer Hewlett-Packard
Product Name Presario C700 Notebook PC
Version F.07
Chassis Notebook
Infrared (IR) Supported No
Machine Type AT/AT COMPATIBLE
UUID E0234741-5D4F-DC11-A876-001B387C5E6B
Model 30D9
Version 83.19
Chipset Vendor Intel Corporation
Chipset Model Mobile PM965/GM965/GL960 Express Processor to DRAM Controller
South Bridge 82801HEM (ICH8M-E) LPC Interface Controller
SMBus Intel Corporation 82801H (ICH8 Family) SMBus Controller @3000h
CPU Intel Core 2 Duo
Cpu Socket Socket 479 [CPU]

HDAUDIO\FUNC_01&VEN_14F1&DEV_5045&SUBSYS_103C30D9&REV_1001\4&2636A2&0&0001

VEN_14F1 is the vendor marker for Conexant.

Based on the chatter at:

http://forum.driverpacks.net/viewtopic.php?pid=13034

...and given the device ID string you gave in this thread, it appears the sound drivers for the HP Pavillion dv6000z from:

http://h10025.www1.hp.com/ewfrf/wc/softwareDownloadIndex?softwareitem=ob-45570-1&lc=en&cc=us&dlc=en&os=228&product=1842155

...will work for your model.  

As noted by souseran: you will need to first load the UAA drivers so Windows has HDA support before you load the drivers.

I was able to fix the problem... I download this exe and then modified the INF file and then updated the drivers.

http://cdgenp01.csd.toshiba.com/content/support/downloads/conexant_audio_os2006203a.exe

added to inf file -
[Conexant]
%HdAudioFunctionDriver.Waikiki5047.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5047&SUBSYS_1179FF31
%HdAudioFunctionDriver.Waikiki5047.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5047&SUBSYS_1179FF31
%HdAudioFunctionDriver.Waikiki5047.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5047&SUBSYS_1179FF31
%HdAudioFunctionDriver.Waikiki5047.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5047
%HdAudioFunctionDriver.5045.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5045&SUBSYS_103C30B7
%HdAudioFunctionDriver.5045.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5045&SUBSYS_103C30BB
%HdAudioFunctionDriver.5045.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5045&SUBSYS_103C30B7
%HdAudioFunctionDriver.5045.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5045&SUBSYS_103C30BB
%HdAudioFunctionDriver.5045.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5045
%HdAudioFunctionDriver.Waikiki5047.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5047&SUBSYS_1179FF31
%HdAudioFunctionDriver.Waikiki5047.DeviceDesc% = HdAudModel,HDAUDIO\FUNC_01&VEN_14F1&DEV_5045&SUBSYS_1179FF31

Ah, you are a registered expert, no wonder. :) Glad you got it figured out.  

I split the points even though I did not find the file in the forum you said to goto it did help me find what I was looking for somewhat.