I believe that what is happening is that you have your display set to
640x480.  With monitors coming down in price in the last few years, more and
more sites are writing their web pages so that they are intended to be seen
at 800x600 or more.  If you have a lower resolution, then you get scroll
bars.  On a 15" monitor, the text may be too small for you to see
comfortably at the higher resolution.  You can test by changing the
resolution for your monitor by going to Control Panel, Display, Settings and
moving the slider.

If this setting is not comfortable for you (text too small), it might be
time to think about getting a larger screen monitor.  You can get a 17" for
under $100 now and I've even recently seen 19" for very near $100.  That
would give you a larger viewing area and you could then increase the
resolution so that the text size was comfortable for you to read at the
higher resolution and web pages fit on the screen without horizontal scroll
bars.

PattyL