New installation

A fairly new PC with 256MB RAM, 30GB hard disk, 2GHz processor, that eventually completed the installation OK, and I didn’t need to use the driver disk as Windows had all the drivers.
After formatting the drive, (I dint need to run FDISK, as it hadpreviously been used for Windows 98), I copied the setup files from the i386 folder on the CDROM to the XP folder on the hard disk. I then ran WINNT, but got an error message that it couldn’t find the files, DISK1, etc. I had to run WINNT from theCDROM, which was ok, but slower. What was wrong? This was not the first time.