In my experience, a few years back, whenever I bought/built a machine I had to explicitly ask for 64bit (if that's what I wanted). Nowadays, it seems to be the

In my experience, a few years back, whenever I bought/built a machine I had to explicitly ask for 64bit (if that's what I wanted). Nowadays, it seems to be the default even for the cheapest builds available. Consider this, most default builds (even the cheap ones) come with at least 4GB of RAM nowadays. The only machines I see with less RAM now are nettops, netbooks and other miniaturized builds. You need 64-bit Windows to fully take advantage of 4GB (with 32-bit Windows, you'll only see like 3.something), not to mention anything larger than 4GB is essentially worthless to a 32-bit OS. Dell isn't going to sell you a laptop advertised with 6GB RAM and then stick a 32-bit version of Windows on there that can only use <4GB. (Now, this 4GB limit to 32-bit OS's isn't a problem with PAE. But why Windows has support for PAE but nobody seriously uses it is a story I don't know the details to.)