This looks like some hardware problem (but "can't install 98SE' is utterly vague), so let's start simple.
1. Take your Windows 98 boot diskette (or download a program to make one from www.bootdisk.com).
2. Set the BIOS to boot from A: first and boot from the boot diskette. Choose cd-support if asked for. Note any error message and note the drive-letter assigned to the cd-drive (could be e: or r:, or anything, depending on the bootdisk used).
3. Put a cd in the drive. Note any error message.
4. Run DOS-diagnostics for A: (dir a:, chkdsk a: ).
5. Run DOS-diagnostics for 'new' hard drive. Should be partitioned and formatted, of course, so do that before if necessary.
6. Do a dir on the cd (no other DOS-diagnostics).
7. If Gateway has them: run other hardware diagnostics from diskette.
8. Reboot from the boot-diskette and choose to install Windows 98 from the CD.
Tell the forum all the results, with as much detail and exactness as appropriate.
I have a old Gateway, given to me, 433Mhz 66buss speed, the floppy drive just started clicking one day, and windows wouldn't load, sometimes after 4 or 5 reboods, well I formated the hard drive, cleaned out the computer of all dirt and dust, replaced hard drive, all the ribbon cables, new bios filmware, and it still clicking, and I can't install 98SE, anybody got any ideas, also anybody know where i can get the bios settings, none in the book, tried default still won't install I took the serial number to gateway, I have all the info. on what's installed, but no bios settings, you think I have a bad floppy drive or a cd/rom. 3 Tec. can't find the problen, and it's not worth paying gateway to fix it.. HELP