I had this problem on my 1992 accord.  There are two reasons, the most
likely is that the form-rubber sealant around the door is old and worn.
I would suggest replacing it, which isn't too expensive at all.

If you're speaking of the window actually not closing all the way, I
would definately suggest getting that loo at.  It could be the track,
or the entire mechanism that closes the window.  It kinda looks like
the thing that "apple-picker" trucks use (like the guys who change the
street lights)... pac man-ish, expanding to push up the window.

Hope that helps,

Matt

My son owns a 1991 Honda Accord LX. On the driver's side the window does
not seal up at the top. This is very loud while on the interstate. does
anyone know how to adjust that window
Thanks,

Billy