Desktop manufacturers don't necessarily design student desktops specifically for college or high school use. Any desktop computer could be considered a student desktop. College or high school students have to decide how they want and need to use their desktop computer. In general I would recommend a dual-core processor, at least 1 GB memory, at least a 250 GB hard drive, a DVD/CD burner, Microsoft Office, and the Windows Vista Premium operating system. You can get student desktops for under $300 but the specifications won't meet what I outlined above. If that's OK with you and you just want to surf the internet, send and receive email, listen to music, watch DVDs and videos, and download or save a reasonable amount of files then check out the cheapest desktop computers on the market today.
There are several good options for choosing a student desktop that will meet your personal needs and wants. I'm going to start you off with