How do you restrict certain hard disk partitions in windows xp for certain users?

you cannot hide disk partitions only folders. if you want your sacred files inaccessible by others put them in "my documents" folder and activate your guest profile. you need to password protect your profile and logout when you intend not to use your pc for a while. other users will log in to your pc as guests and they cannot delete or see the contents of your documents.

why not just change the permission of the partition drive you can do it. just log as administrator, right click the partition, sharing and security. from there you can click advance and the permission.