been having this fun at work this week - if all else fails try this....
Remove as much as possible through add/remove programs, once its out of there go to program files and look for folder called 'cosids' delete everything from here and the folder itself.......
Create a folder on the desktop, copy all the info from the Cosids folder on DISC1 into the folder on the desktop - then remove the cd.
Go into the folder on the desktop and run the main install file - it should not start to install (it could still say 'tis is still running') - it will get halfway then ask you to install disc 2 -
put disc 2 in, and again copy all the info within the Cosids folder to the folder on the desktop, once its all there, click ok on the Tis installation, and that will carry it on...... and bobs your uncle......hopefully.....
we've had this issue so many times it silly, just found this way to work best at work...... running 98, 2000 and ME on different systems....
try that