Do you have drivers for Windows 98?
Click on the 'Start' button, point to 'Settings', and then click on 'Control Panel'.
Double click on the 'Display' Icon.
Select the 'Settings' tab then click on 'Advanced...'.
Select the 'Monitor' button, then click on 'Change...' button.
Select 'Specify the location of the driver(Advanced)' and click on the 'Next' button.
Select 'Display a list of all the drivers in a specific location, so you can choose the driver you want', then click on 'Next' and then click on 'Have Disk...'.
Click on the 'Browse...' button, select the appropriate drive F: ( CD-ROM Drive) then click on the 'OK' button.
Click on the 'OK' button, select your monitor model and click on the 'Next' button.
Click on 'Finish' button then the 'Close' button.