I want to make it so that linux doesn't have any access to my windows partitions.

Remove from /etc/fstab

Welcome to LinuxQuestions.

What distribution and version are you running?
Are the Windows partitions automatically mounted?

Does your unknown Linux OS have access now? And as asked above, check the /etc/fstab file for entries if they exist and comment them out or remove them. When you installed Linux, were you informed that windows partitions had been found and asked if you wanted them available on your Linux? If so, your answer should have been no then there would be no entry in the fstab file. Some Linux systems might not do this so?

Not sure what problem you foresee but the Linux OS isn't going to access your windows without user intervention.

In case it may help, here's a pretty good tutorial on the /etc/fstab file.

Hi,

Welcome to LQ!

I agree with other mentions of removing from '/etc/fstab' the entry relative to your windows partition(s). Please remember that any time you want to make changes to the system you will need root privileges as root or to use sudo.

But to answer your subject line query the means to unmount a partition is to use a 'umount /MountpointForWinPartion'.

To look at your mounted partitions you can use the 'df -h' to show them. 'df' will show the mount points and the free space on each. Again be sure to look at 'man df' to understand the command.

Look at 'man umount' from the Command Line (cli) within a virtual terminal. To umount a system mount point you will need to be root or use sudo. Remember to learn from 'man command' so you can perform the commands as desired.

Please look at my sig for some useful informational links to help you with the command line work.

Hope this helps!