|First you should probably do a FIND--FILES OR FOLDERS search and see if the file is there.|
I think it's MSO9.DLL and not MS09.DLL, that is 'oh' 9 and not 'zero' 9.
If it's not there, I already checked and it's not on the 98 cd so must be on the Office cd. If that is a separate disk for you then you should probably go to add/remove programs and see if Office has a 'repair' option. If not you can probably uninstall and then reinstall Office.
I don't know how you'd do it if everything is on your Dell restore disk. There are download sites for files but you'd need the correct version.
Depending on the exact wording of the error message, you may be able to google it and find something. I googled just "MSO9.DLL" and got some links to microsoft.
Onward to 300