In that case, my original suggestions are still valid.
#1 Use Task Manager to verify what process is using the CPU time when you
shut down Excel. It may not be Excel itself - it could be an add-in within
Excel.
#2 Check the amount of available space on the hard drive you are writing to.
It could be low.
#3 If it is Excel, then using your original Office/Excel 2000 CDs, you
should be able to do a repair installation (basically installing from the CD
using the same settings you originally used). This can cause some updates to
require re-installation after the repairs are complete.
#4 There may be a hardware issue with memory (RAM) involved. A good test
for your memory is Memtest86, available as a free download from:
http://www.memtest86.com/ once you start running it, it will run until you
stop it. The longer you allow it to run, the more opportunity it has to find
a bad memory card. Consider starting it when you leave the office/go to bed
and letting it run overnight.
#5 Least likely since we are only talking about one application being
affected, but not impossible, would be a virus on the machine. Run a full
scan of your system using your installed anti-virus program, plus consider
running some of the on-line tests from sites like (these are all reputable,
good anti-virus companies)
Kaspersky Labs scan (I use KAV products and trust them very much), at
http://www.kaspersky.com/virusscanner
eset's product:
http://www.eset.com/onlinescan/
F-Secure:
http://support.f-secure.com/enu/home/ols.shtml
Trend Micro's Housecall:
http://housecall.trendmicro.com/
BitDefender scanner:
http://www.bitdefender.com/scan8/ie.html
Panda Security's scanner:
http://www.pandasecurity.com/homeusers/solutions/activescan/
and of course, the standard ones provided with most new systems (and thus
the direct targets of many viruses and worms)
Symantec (Norton) :
http://security.symantec.com/sscv6/default.asp?langid=ie&venid=sym
McAfee:
http://us.mcafee.com/root/mfs/default.asp
there are other reliable, reputable ones also, but if you can pass through
those, then you have a clean machine. There are also others that are not so
reputable and will falsly report problems just to sell you their product.
Never take the results of just one site/product's tests as the absolute
gospel.