I have an old Dell Vostro 1000 laptop running Ubuntu 11.10 for desktop. It originally came with Windows Vista Basic, got upgraded to Windows Vista for Business, and proceeded to get slower and slower with each Windows Vista update.
The hardware only supports so much memory, so I hit that limit long ago. It was taking several minutes to boot. I considered ordering a recovery disk to restore it to factory settings; but, decided that after all the Windows updates installed again, it would probably not be much faster.
Given that I had been avoiding use of the laptop due to the long boot time, I went for it and installed Ubuntu 11.10 for x86. In retrospect, I should probably have chosen the 64 bit version. The laptop has an AMD 64 bit Athlon X2.
I don't know what difference running the 64 bit version will make.
Tonight, I noticed that Ubuntu is now testing 12.04, Precise Pangolin. So, rather than doing a straight upgrade, I'm downloading the 64 bit version. I'll be installing from scratch. I haven't had the laptop running on Ubuntu long enough to get sentimental about it. Actually, most of my work is cloud-based, so there is little chance I'd have anything on the laptop worth keeping.