OS XP sp3


MS Office 2000
IE8
I have several .xls files, none of which save the data before exiting.
I fill cell with data, select the square disk or file save or select the upper right X and in every case the file closes, and upon re-opening no data save was made.
MS Office Word functions correctly.
Uninstalled MS Office 2000, re-installed Office 2000, updated same. All .xls files display okay but do not save data.
Brought Windows up using Repair Console & executed an R(epair).
Ran Microsoft Updates downloading all available updates.
I'm out of ideas, HELP!