Forum Moderators: open
The main issue will be the power supply. US plugs will not fit, so he'll need an adapter. Also, the voltage in Russia is 220 V, so the laptop will need a converter or a power supply that supports different voltages.
Also don't forget the keyboard. I use my laptop together with my wife and she only understands Russian. I painted the Russian alfabet on the keyboard with a black marker. I used nail polish as protection and the characters are still there after three years. But I wouldn't recommend this procedure for a new laptop...
Power supplies are often not a big problem. Laptop manufacturers know that their product may be used in different countries and they often use a power supply model which accepts voltages from 100 to 240 VAC. You only have to change the powercord or use an adapter.
<added>
Did a search on the Microsoft website. The Multilingual User Interface pack is only available on Windows XP Professional, not in the home edition. So if you buy a laptop with XP Home, you can probably only change to Russian by reinstalling the OS from an installation CD. More information at this page: [microsoft.com...]
</added>