Yeah, that dell restore disk won't work with a new PC.
I would go with XP for a new system, if it were me. XP has more features and security than Win. 98, and is more reliable. You can buy XP Home edition as OEM, from most online stores...to qualify as OEM (cheaper) you just need to buy a computer part with it.
CPU - P4 2.4C, 800FSB W/HT - CONSERVATIVELY OC\'ED
MOBO - GIGABYTE GA-8KNXP 2.0 875P CHIPSET/DUAL BIOS VER. FE
RAM - 1GB (2X512) OCZ PC3200 REV 2, 400MHZ 2-3-3 6
VID CARD - ASUS RADEON 9600XT 128MB W/VIVO
FLOPPY - SAMSUNG 1.44M
HDD - MAXTOR 120GB 7200RPM ATA133 EIDE W/8MB BUFFER
DVD - LG GDR8162B 16X IDE DVD ROM
PSU - ENERMAX EG465P-VE FC 460 WATT
VANTEC VP4-C7040 AEROFLOW HS/FAN
5 X VANTEC STEALTH 80MM CASE FANS