If you want to completely remove a Linux installation (or any other operating system, for that matter) from a hard drive, just delete the partition(s) the operating system is installed on using suitable partitioning software (fdisk, etc.). Then create new partition(s) for the operating system you want to use.
Hmm so if I have linux on my second partition and I delete it linux is gone?
There are two aspects of a booting OS. It's boot pointer and its installation location.
If both are on the same first primary partiton then wiping the partition will delete the OS as well as its boot pointers.
Otherwise you need to remove the OS partition as well as setting the boot pointers on primary partition one to something else. You can do this by installing a different OS or just removing all boot files/mbr.
"Hmm so if I have linux on my second partition and I delete it linux is gone?
Hmm, Well, 'fraid so.
If you've deleted the linux partition and then created and formatted a new partition, linux is gone. If you've foolishly left some "boot pointer" to the previously existing linux boot code, there will be no linux boot code where it's "pointing". Linux will be gone.
The information on Computing.Net is the opinions of its users. Such
opinions may not be accurate and they are to be used at your own risk.
Computing.Net cannot verify the validity of the statements made on this
site. Computing.Net and Purch hereby disclaim all responsibility
and liability for the content of Computing.Net and its accuracy.