Reader Mike ordered a new Dell system that came with a 21.5-inch LCD monitor. Although the monitor includes VGA, DVI, and HDMI inputs, it included only a VGA cable--even though the setup instructions recommend a DVI or HDMI connection! Mike wants to know why, and whether he should bother buying a different cable.
I'm going to answer in reverse. First, I would indeed recommend using a different cable to connect your monitor to your PC. However, there's no need to bother with HDMI unless you're planning to watch Blu-ray movies (assuming your PC has both an HDMI video output and a Blu-ray drive).
Even then, DVI also supports the HDCP protocol necessary to view that kind of protected video content. HDMI is really best for connecting a PC to an HDTV.
Consequently, I'd go with a DVI cable. That'll give you a pure digital signal (VGA is analog) and a much sharper picture at higher resolutions. Your Dell ST2210 has a native resolution of 1,920 x 1,080, which you can and should use.
So, why do most monitors come with only a VGA cable? Probably because VGA is still the most common type of video connector worldwide, and, consequently, the mass-produced cables are cheap. Vendors could supply DVI cables as well, but then at least one would be going to waste.
There you have it, Mike. Drop a few extra bucks and treat your high-falutin' monitor right.