There is no supported upgrade path from WinME to Windows 2000. To do a clean
install, either boot the Windows 2000 install CD-Rom or setup disks. The set
of four install disks can be created from your Windows 2000 CD-Rom; change
to the \bootdisk directory on the CD-Rom and execute makeboot.exe (from dos)
or makebt32.exe (from 32 bit) and follow the prompts.

When you get to the point, delete the existing NTFS and or other partitions
found. After you delete the partition(s) abort the install, then again
restart the pc booting the CD-Rom or setup disks to avoid unexpected drive
letter assignments with your new install.

Be sure to apply these to your new install before connecting to any network.

http://download.microsoft.com/download/E/6/A/E6A04295-D2A8-40D0-A0C5-241BFECD095
E/W2KSP4_EN.EXE
http://www.microsoft.com/technet/security/bulletin/MS03-043.mspx
http://www.microsoft.com/technet/security/bulletin/MS03-049.mspx