If you have a CRT monitor that works well and looks okay, my advice is to keep using it until it is no longer good enough. Amognst other advantages, video and motion will look better on most CRT monitors, and the display will look equally clear in any resolution - that is not the case with LCD monitors.
The ATI 9550 chipset came out long before 22" LCD screens, especially widescreen ones, were available. Chances are high there will not be a video setting available from the video drivers for the card for the optimal resolution setting a 22" monitor is specified to preferably use, especially if it is widescreen like most are these days, even if you update the video drivers to the latest ones.
1024 x 768 is a standard width to height ratio - most new monitors are widescreen. If you use a standard resolution setting on a widescreen monitor, it will look stretched width wise. For a widescreen display, you need to choose a resolution with the same or a similar widescreen ratio so that the dislay doesn't looked too streched.
All LCD monitors have a specified optimal resolution - the display will not look as good and text will not be as clear in other resolutions. If the monitor you buy is reasonable quality, it will probably still look pretty good in other than the optimal resolution (e.g. Samsung models I've seen do) but cheaper brands probably won't.
You can get a rough idea (you may not be able to find out for sure until you load the specific monitor drivers for the monitor you get) by checking out the resolutions available for your card in Display - Settings - with the monitor set to Plug and Play Monitor - is the optimal resolution you preferably need for the monitor you were thinking of buying available, or at least a lesser one with the same or a similar (widescreen?) width to height ratio?.
Get a monitor first, preferably one of higher quality which will probably cost a bit more, and try it with your existing card. Load the specific monitor drivers for it, then Windows will by default show you only the settings both the monitor and the video drivers can do - you may be able to make a good enough compromise, even if you can't set it to the optimal setting. You could try loading the latest 9550 drivers, but it may not change what settings are available.
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Turn on Clear Type in Windows XP or Vista - makes type/fonts on LCD screens look clearer.
http://www.microsoft.com/typography...
"Load the specific monitor drivers..."
Cheap monitors may not have specific monitor drivers - they use Plug and Play Monitor settings - avoid those like the plague if the optimal resolution you are supposed to use is not listed when you use the "You can get a rough idea ..." method).
