Thanks for your reply! I managed to get it done before I got your info. I'm looking for XP compatible drivers for a few things listed in XP's Device Manager now:

Conexant HD Audio
Base System Device
Base System Device
Base System Device
Unknown Device

Any idea what the Base System Devices might be?

HP only has HP Wireless Assistant and Quick Play Button drivers for XP on their site. Not much use! Could any of them be a card reader? I haven't installed anything for that yet.

Ok I finally got everything working. Here's how to dual boot XP and Vista on the HP dv2550se...

Download the Intel floppy creation utility which includes the SATA driver you'll need:
http://downloadcenter.intel.co.....8;lang=eng

Make the floppy and extract the drivers, then integrate the driver on a custom XP install cd using nLite (www.nliteos.com). There are plenty of guides on how to do this.

In Vista, right click “Computer� and choose “Manage�. Here you can resize your Vista partition and create a new NTFS Logical partition in the empty space. Install XP on the new partition.

When it's installed, in Windows Explorer go to Tools - Folder Options - View and choose to show hidden files and show protected operating system files. Then copy the boot folder, boot.ini, NTDETECT.COM, bootmgr and ntldr from the root of your Vista partition to the root of your XP partition.

Now download and install Microsoft's .NET Framework 2.0
http://www.microsoft.com/downl.....laylang=en

Next download and install Vista Boot Pro:
http://www.vistabootpro.org/

Open Vista Boot Pro and make a backup of your BCD file as instructed. Now go to �System Bootloader “and check "Windows Vista Bootloader". In the "Install Options", choose to install to a "Specific Drive� and choose your "C" drive. Click "Install Bootloader"
Next go to "Manage OS Entries" and add an entry for XP, choosing "D" as your "Boot Drive". Click “Apply Updates�. Now XP and Vista should be bootable. You can set which is the default to boot and how long you should have to choose an OS here too.

Next, download and install Microsoft's DirectX 9.0c.
http://filehippo.com/download_directx/

Now download and install the Intel GM965 Chipset Driver, GM965 Graphics Driver & the Matrix Storage Manager. You can get them all here (top row):
http://support.intel.com/suppo.....025753.htm

Reboot if needs be.

Get the Marvell Ethernet Adapter driver here:
http://www.marvell.com/drivers.....&pId=6

Get the Intel Wireless Adapter driver here:
http://downloadcenter.intel.co.....me=Windows*+XP+Professional&lang=eng&strOSs=44&submit=Go%21

Install the two network adapter drivers.

Next, download the Ricoh Card Reader drivers for Vista:
http://h10025.www1.hp.com/ewfr.....38;lang=en

Extract them to a folder, then use the drivers in the x86 folder to install each "Base System Device" manually using Device Manager... i.e. Right click "My Computer" and go to "Devices". Now choose "Hardware". Scroll down til you see the three "Base System Devices".
Right click the first "Base System Device" and choose to “Update driver�. Choose "No, not at this time" and click next, then choose “Install from a list or specific location� and click next. De-check “Search removable media� and check “Include this location in the search�. Browse to the MS folder within the x86 and install click next. Now repeat this process for the second “Base System Device�, this time choosing the MMC folder as the search location. Now do it for the third, choosing the xD folder as the search location.

Download and install the Microsoft Universal Audio Architecture before installing the audio driver:
ftp://ftp.hp.com/pub/softpaq/s.....p33867.exe

Download and install this Conexant HD Audio Driver:
ftp://ftp.hp.com/pub/softpaq/s.....p34386.exe

Download and extract the Vista Conexant Modem drivers and run the “Setup.exe� in the V32 folder:
http://h10025.www1.hp.com/ewfr.....38;lang=en

Download and install the HP Quicklaunch Buttons:
http://h10025.www1.hp.com/ewfr.....38;lang=en

That should be the final missing device in Device Manager:

The Lightscribe Software and the HP Software Updater and Wireless Assistant aren't really necessary but you can get them at:
http://h10025.www1.hp.com/ewfr.....38;lang=en

Hope that helps!

Thanks! I made a slight mistake in the Ricoh Card Reader bit. I meant to say right click "My Computer" and go to the "Hardware" tab... then click "Device Manager". Not the other way around as I wrote. You get the idea anyway.

Yeah I think there will probably be more and more people who want to install XP on this machine in the near future. XP runs REALLY fast on it and I've seen a HUGE improvement in wireless networking especially. Pages load ten times faster and downloads finish much quicker too. Certain things like pro audio applications and hardware are much more stable on XP too. I like how Vista looks though and I think it will be useful in the future when it's more mature and when there's a bigger range of software/hardware available for it. Also, there is no Vista install cd included with this computer so I think it's best to dual boot for now. I'll probably try put Ubuntu on it too. I'm not sure if Grub will recognise Vista though. Does anyone know? Maybe that's a question for another thread!

Anyway, this information was gathered from a variety of sources and ALOT of trial and error. The Conexant HD Audio driver was particularly difficult to find. Hopefully they will find your article or one of the threads I've posted all the info in and save themselves alot of bother! Here are the other threads:

http://forum.notebookreview.co.....#38;page=2
http://forums.techguy.org/wind.....ves-2.html
http://www.davesdrivers.com/fo.....#38;page=2

Thanks to everyone for their help!

great writeup Eli!
I have a HP Pavillion DV6433CL that I purchased from Costco, preloaded with Vista.
According to HP support, this is not the retail version, so dual-boot will not work.
I have a retail version of XP Pro which I want to install so that I can use VPN and work stuff.
I installed XP Pro, reformatted the C: drive. After the install completes, the system keeps rebooting with a boot.ini message that flashes very fast.
any thoughts??
Thanks.

would the instructions work for the hp dv6000 as well?

I managed to install XP media centre edition over Vista home premim with no problems (reformatted HD), but anything I now try to install on XP gives an error. I can install the same program on my laptops with no problem

Can this be a driver I am missing???

Hello everybody.. i'm new here and i really need your help !
I bought a new Sony Vaio VGN-FZ29VN and it came with Vista Busines installed, but with no other discs such as drivers or anything. I want to install XP on a new partition that i already created.. i have the same problem as many have..the boot XP cd does not recognize my hard drive. The bios does not have the acpi function to operate with it..what can i do? nlite does not open in my Vista.. i do not have an external Floppy drive.

Hi everyone
recently i bought HP pavilion dv2550ee with vista. I want to switchover to XP. Even i was successful in loading XP. The only problem is lack ofXP drivers. HP doesnot keep all necessary drivers in the site except few. How to get complete set of drivers? please advise me if someone does this before.