Compaq Presario CQ40-305LA is powered by Intel Dual Core 2.0 GHZ  processor. It comes with 160GB ( 5400RPM ) HDD, 2 GB 800MHZ DDR2 RAM, 14.1plg.Diagonal WXGA High-Definition, HP BrightView Widescreen Display (1280 x 800), DVD with dual layer support and so on. It comes pre-installed with Windows Vista Home Basic System. But if you have downgraded your laptop from Vista to XP, then you will probably face a lot of issues especially regarding drivers. This is because HP Compaq does not support Windows XP anymore. But all is not last. We have compiled the different steps required for the installation of drivers for Windows XP. 

Kindly check the link to know more about Issues regarding downgrading to or installing Windows XP in HP-Compaq systems

Neither Zyxware Technologies, nor HP-Compaq can give you a guarantee that these drivers will work perfectly in your system. How ever, you may try installing these.

You can either click or copy the given link and paste them onto a new driver to download them.  

This model of Presario has an audio controller that supports the high definition audio. You need to have Microsoft Universal Audio Architecture (UAA) Bus Driver for High Definition Audio installed on the computer before installing the audio driver.

Here is the link for the Microsoft Universal Audio Architecture driver that need to be installed before installing the audio driver:

Microsoft UAA driver:

ftp://ftp.hp.com/pub/softpaq/sp33501-34000/sp33867.exe

After installing the UAA driver reboot the notebook nad install the audio driver from the following link:
 
Audio driver:

ADI SoundMAX AD1984A Audio Driver:

ftp://ftp.hp.com/pub/softpaq/sp39501-40000/sp39695.exe

Installing this driver may result in an error. But continue with the following steps to get the audio driver installed correctly.

Chipset drivers for XP:

http://downloadcenter.intel.com/Detail_Desc.aspx?agr=N&ProductID=816&DwnldID=16023&strOSs=44&OSFullName=Windows*%20XP%20Professional&lang=eng

NOTE: However, this will take you to a third party site. HP does not control  the content published on this site.

Video driver for XP:

http://downloadcenter.intel.com/NotFound.aspx?NotAvail=Y&lang=eng

NOTE: However, this will take you to a third party site. HP does not control  the content published on this site.

High-Definition Audio (HDA) Modem Installer and Driver:

ftp://ftp.hp.com/pub/softpaq/sp39501-40000/sp39545.exe

Intel PRO/Wireless Drivers :

ftp://ftp.hp.com/pub/softpaq/sp38501-39000/sp38890.exe

Synaptics Touchpad Driver:

ftp://ftp.hp.com/pub/softpaq/sp39001-39500/sp39032.exe

Marvell Yukon Gigabit Ethernet Controller Driver:

ftp://ftp.hp.com/pub/softpaq/sp39501-40000/sp39955.exe

HP WWAN Connection Manager:

ftp://ftp.hp.com/pub/softpaq/sp37501-38000/sp37761.exe

Chicony Camera Driver:

ftp://ftp.hp.com/pub/softpaq/sp39001-39500/sp39323.exe

If the issue persists, please contact us by visiting the following Web site. We will be glad to assist you further.

http://forums12.itrc.hp.com/service/forums/bizsupport/questionanswer.do?admit=109447627+1221738235132+28353475&threadId=1264202

Video driver :

http://www.findmysoft.com/drivers/ATI-Catalyst-8-4-Display-xp32-video-card-driver.html

Audio driver :

http://www.versiontracker.com/dyn/moreinfo/win/151979

Ethernet(LAN) driver :

http://www.downloadpipe.com/drivers-network/review-Realtek-RTL8102E-Family-PCI-E-Fast-Ethernet-NIC-1195806.html

OR

http://www.radarsync.com/driver/d275927-realtek_rtl8102e_family_pci_e_fast_ethernet_nic 

 
http://welcome.hp.com/country/us/en/contact/chat_1.html

Or

http://h20180.www2.hp.com/apps/Nav?h_pagetype=s-006&h_lang=en&h_cc=us&h_product=18703&h_client=S-A-R163-2&h_page=hpcom&lang=en&cc=us

Installation Instructions:

1. Download the Softpaq .EXE file to a directory on your hard drive.

2. Execute the downloaded file and follow the on-screen instructions.

3. Restart the notebook when the installation is complete.

Download these files and save them for back up for future use. Incase you have any queries, feel free to contact us with your queries and suggestions.

Our Address:
Zyxware Technologies
3/118, Kesavadasapuram,
Pattom P.O,
Trivandrum - 695004
Phone: 0471-2449495
Mobile: +91-9446-06-9446
Email: info@zyxware.com
Website: www.zyxware.com