Can't Open Normally

Our network is 5 workstations and a server. All stations are running XP and
the server is XP Pro 64. For some reason we have yet to understand, one of
the stations no longer can open a document through what we have come to know
as normal: Start - My Documents - Document, or Desktop Shortcut - Document.
Whether it's a docu on the workstation or on the server each attempt gives an
error message saying Windows cannot open the document. If the program is
opened first, such as Word or Excel, then the docu can be opened by File -
Docu - Open or Open Icon - Docu. In addition to that, at the same time those
symptoms appeared, when an IE7 window is opened, instead of the label on the
tool bar giving a short description of the page that's open, all that shows
is the first letter of the description. Then, as if all that isn't enough,
attachments in OE6 cannot be opened. The operation of the station is not shut
down, just crippled a bit, so we are getting along, it's just slower and a
bit frustrating. Any ideas of what may be going on and especially any ideas
for corrective measures will be greatly appreciated. Thanks, K.