I want to buy a laptop at some point in the near future, but not knowing beforehand whether it works with Ubuntu makes the whole operation risky and tiresome. I would like to know if there is some kind of official hardware database where I can enter the name of the laptop I'm interested in and see if it's 100% compatible out of the box, or in case it isn't what is it exactly that doesn't work (ideally also if there is a way to fix it).
Does Canonical have a project along these lines?
When I bought mine, I simply brought a live CD in the store, and asked to try it on their laptops. I explained them what this is, and that I want to check the compatibility of the different components with Ubuntu. I sometime had to explain what Ubuntu was...... One place told me a flat NO, that I could not try it. I ran out of the store as fast as I could. At the store where I actually bought my portable (in Dec. 2006), I tested that the display was actually working on the internal monitor, at the full resolution, as advertised on the spec sheet, that the wireless adapter was found, and that I could use the card reader, with a card I brought in. I finally tested the sound itself, which was rather easy to do.
Today, you could bring Linux on a USB disk instead, or even an SD card. Also, in 2010, you should expect every sales rep on the floor to be at least know about Linux. Usually, they should understand that starting it from a CD, especially if this is a branded one, not burned at home, there is no harm that will be done on the machine.
NOTE: The fact that some components are not discovered right at boot from a live CD does not mean that Ubuntu will not support it. Chances are that you will find the proper driver for it. You will just have some manual setup to do.
You may also want to note the brand names and models from a store and check on the net, with Google. You should usually find either some test cases or message exchange about it that will give you a good idea about the model you are looking for.
This will help you: Ubuntu hardware partners
See also:
While I upvoted the idea of trying out a LiveCD or LiveUSBStick, if you can't do it at your favorite store, here are some thoughts...
You might check on Craigslist - there are some great deals on year-old laptops, and if you're carrying cash, an individual might be more willing to let you test Ubuntu on it.
If you really want to buy new, and you can't test, my experience doing many dozens of Ubuntu installs over the last five years says there are only a few things you're likely to have problems with:
Multiple drives in a weird fakeraid configuration - I'm looking at you, Sony. You can prevent this by making sure the laptop only has one hard drive. (For more details, look here and here.)
Bleeding edge wi-fi or Ethernet controllers; sometimes it takes a while for support for those to make it into the Linux kernel. There are compatibility lists, and in any case, if a laptop's controller chips are from a major manufacturer (e.g. Broadcom, Intel, etc.) and have been out for a year, you should be okay.
Bleeding edge GPU. Same as for the wi-fi and Ethernet controllers; the manufacturer names are just different.
I've never had a Ubuntu compatibility problem with a reasonably modern x86 CPU, motherboard, memory, etc. It even ran fine on my creaking old 2000-era HP laptop before I recycled it. So I'd guesstimate that if a laptop passes 1-3, chances are 99+% it will be fine with Ubuntu.
This may also help you.
http://www.linux-laptop.net/
As it was written in another answer by linuxbuild: