I have a windows 98 and everytime I turn it on it comes up "No operating system". Please help!

Well, It could be that your startup files are corrupted. Try booting from the Windows 98 cd, or a boot disk. At the DOS prompt type: fdisk /mbr and hit enter. When it's done, remove the cd or floppy from the computer and restart it. See if you still get the error.

By the way, does your hard drive start when you start your computer? You should be able to hear it just by getting close to it. Do you hear any odd sounds or "clinking" noises?

You can get a bootdisk from here:
BootDisk (http://bootdisk.com/)

Hope it helps.