"how do I get a computer without all the crap that they usually install on them?"
Common question, with multiple answers.
Some of the vendors, as well as some retailers, offer crapware reduced (none are completely crap free) PCs. The specialized gaming vendors, and Apple all put minimal crap on their systems.
Personally I prefer buying OEM hardware, and my own OS and installing myself. You can buy OEM machines whole, or in parts (even laptops) from various vendors online; and get decent pricing on "system builders" OEM versions of windows.... Or you can install Linux, BSD, or Hackintosh the thing if you so choose(and I frequently do).
Of course, one of the advantages (if you want to call it that) of buying standard hardware, is that every major vendor PC (unless specifically ordered with linux or without an OS;and some vendors do allow you to do so) will come with a windows license. That means you can reinstall windows (on that machine only of course) as much as you want.
If you're stuck with a stock major vendor laptop (a common situation), and you don't already have an OEM windows install disk (everyone should keep a couple around), and don't want to download one off the net (completely legal as long as you have a license, but Microsoft doesn't like it, and there's always the risk of malware); contact the manufacturer and insist on a windows install disk, not just a factory restore disk (or at least a way to use the factory restore disk to install clean).
They may charge you $40 for it (they are allowed to charge a "reasonable fee" for media. Most have settled on something around $40) but vendors are required by the windows license to make a method of windows install (other than "factory restore") available to you.
Of course as I said, that may be an option on the factory restore disk; or it may be a hidden partition on the hard drive that you can burn a CD from, so don't wipe the drive until you're sure.
Once you have your install media, you can (and I think, generally should) wipe the thing, and reinstall clean. Before you do though, make sure you have the video, sound, wireless, ethernet, and mouse drivers, just in case. The latest couple versions of windows are pretty good about driver detection and installation, but by no means perfect.
Or you could just buy a Mac, or run Linux in the first place...