I'm not entirly sure if this is the place to post this,
but I'm running low on options, so here goes:

I recently installed Windows XP(about three months ago),
and have been running into various problems since; at one
point the system would not even boot up, forcing me to
reformat and re-install Windows XP. Now, ever since that
point, an error has been occuring, seemingly everytime I
connect to the net through Explorer, and shutting my PC
down if I attempt to close the box--so instead I end up
leaving the error box on the screen the entire time. The
box itself states "lsass.exe - Application Error" and goes
on about memory not being read... which leads me to my
newest problem, memory.

My hard disk has a capacity of about 14.2 GB, and just
hours ago, had about 1 GB free; however, at some unknown
rate the memory is constantly dropping. It is now at a
mere 500 MB, and dropping. Over this period of time I have
done nothing to cause such a memory loss(ie: downloads,
etc.), yet it still goes on; I have tried rebooting, but
it stays the same; I have tried scanning for viruses--
found a few, though I'm not sure I got rid of them
completly--and spyware; I am defragging now, even though
it won't do much good without 15% disk space free. At this
rate... well, I'm just out of ideas.

I'd really appreciate any help, even a friendly point in
the right direction. Thanks.