My wife recently bought me an Acer Extensa 5620 for Christmas. It's a great little unit with a lot of potential, but the one big flaw was the operating system: it came with Windows Vista. The fast hardware was crippled by the bloated, clumsy OS. I was therefore forced to figure out exactly how to get XP on it, so wrote up a guide to help others. It should apply to different Acer notebooks, and likely has info useful to other brands as well. It's not as simple at it used to be.

Drivers and Manuals. Drivers and Manuals. Identify your Acer Device. Download our serial number detection utility. (Windows operating systems only).

Today's laptops are 'meant' for Vista, so trying to install XP often isn't easy. In the case of my 5620, the hard drive wasn't even detected until I researched and changed Bios settings (known as the AHCI issue). I'm SO much happier after ditching Vista, though- when I first got it, a 1GHz Pentium III with XP could have run circles around it! Don't immediately wipe Vista! It's actually useful for another hour or so. Use Acer's backup software (mine had an Acer floating toolbar with this) to do two things- First, a Full Backup of your system. Trust me, if you ever have to send your Acer in for servicing, it better have Vista on it or your warranty could be voided.

Plus, someday when you sell it, uninformed people think it's a plus point;) Secondly, why bother downloading random drivers you hope are the right ones? Acer makes it easy with its Driver and Application backup CD creator. A little known fact is that these drivers appear to be both the complete Vista AND XP set. Once you're done, you'll have burned three DVD's, and be ready for some XP goodness! If you've already wiped it, or just want the latest available, grab them from [ftp://ftp.support.acer-euro.com/notebook/ here].

I did both, just in case, throwing the newest onto a 256MB USB drive. Thirdly, look in Device Manager to see what AHCI Disk Controller you have! Write this down. On the Best Buy Acer Extensa 5620-6830, it's the 'Intel 82801HEM/HBM SATA AHCI.' Other models may be slightly different.

This info is important later, and it can be difficult to find out without some annoying trial and error. Once we're at the desktop, change your resolution to 800x600, then start installing drivers (some setup program buttons are cut off in the default 640x480). You probably want to start with the chipset driver, then the video drivers, sound, etc. On the Extensa 5620, even after installing the drivers you will likely have no sound at first and end up with a 'PCI Device' that is unknown; just right-click it and choose Update Driver. Let it automatically find it (it's the HD audio), and your sound should work after the next reboot. I rebooted every time it wanted to, then installed the next driver. This way they don't clash or get misconfigured.

The webcam driver (both original and latest on the FTP) appears to install and work fine, but makes your system permanently hang when shutting down. Until we get a better driver, I just disable it to avoid having to hard crash every time. In theory, you can just enable it whenever you need to use it.

Everything working OK now? No exclamation marks or unknown hardware? Now let's conquer the AHCI issue. On the driver CD, browse (don't auto-run) to the Drivers directory. Copy the AHCI folder to your C: drive, so now it's c: AHCI.

Open the command line (Start -> Run -> cmd), and enter 'c: AHCI setup.exe -a -pc: ' (without the quotes). This will pop up the setup utility. Click through it- it's not actually installing, but extracting the drivers for us to use. You'll find them afterwards in C: Driver.

Now we manually install the driver into XP: Go to Device Manager, under IDE ATA/ATAPI controllers you should see something like: ICH8M SATA Controller. Right-Click on that and select Update Driver. Choose No to connecting to Windows Update to search, then hit Next. Select Install from a list or specific location (Advanced), hit Next, then select 'Don't search. I will choose the driver to install.'

Hit Next again, then select Have Disk. Browse to your Drivers folder (C: Driver), highlight the iastor.inf file, and hit Open. Select OK, then choose your AHCI driver (what we wrote down earlier, remember?).

You'll likely have to uncheck the 'show compatible hardware' option to see the AHCI options. Again, on the Extensa 5620-6830, it's the Intel 82801HEM/HBM SATA AHCI Storage Controller- YMMV (Your Motherboard May Vary). Click next, ignore the warning that installing the device driver is not recommended, click Yes, Finish, then Yes to restart your computer.

When your computer reboots, hit F2 again to enter the BIOS. I changed my boot order back to HD first (shaves a whole 2-3 seconds off bootup time), but that's up to you.