if you are in windows 2000 then
Start-->Setting-->Control Panel--->Administrative Tools-->
Computer Mangement-->Storage--->Disk Mangment
you will see the visual view of disk partitions, right click on the linux paritions then either delete or format them.
Be carefule by mistake do not delete the windows partionts. For linux partitions most likely file system will NOT be FAT/FAT32/NTFS
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use some tools like Patition Manger, Partiton Magic to delete linux partitions.