Hi, I've enabled disk quota on my DC, we create and delete user accounts frequently, i noticed that there are few entries in disk quota entries window "[account Information Unavailable] followed by SID", it occupies some space also on disk but i couldn't file those file, hence couldn't delete this entry. Kindly help me to remove it.

I'm not sure offhand about your problem but if you don't mind some advice.... In the future, stop deleting accounts. Just disable them when the user leaves or whatever. That way in the future, you can reuse the same account by simply renaming it and applying a new password. If you think about it, person A leaves the company, you hire person B to replace A. You want B to have the same type of account with the same group memberships and perm's etc. It's a LOT easier to rename account A to B and give it a new password than it is to create a whole new account and give it the same group membership and perm's etc.

Goto the folder that matches the quota entry and amend/reset the permissions so you are the owner of the folder. Once you have taken ownership you can delete it and the quota entry for the folder will dissapear. BTW how many users do you have? You may want to consider a dedicated file sever