How to disabled/enabled Delete permission in in Defect module?

User group has no DELETE permission in DEFECT module. How can I enable  it for user group in all domain including all projects within it?

And the following are the different answers I got for this :

1. The first solution:

I am using QC 10.0, and here is how I would try to solve this issue in QC -- note these changes are at the project level (not domain level):

* Navigate to (Tools, Customize) menu commands.
* Click the (Project Users) link.
* Find your user in the list and note to which group they belong.
* Click the (Groups) link.
* Select the group to which your user belongs.
* Click the [Change] button - in the Permissions group on the right side of the screen. This displays a [Permission Settings] window.
* Navigate to [Defects] tab.
* The 3rd command in the displayed list is [Delete Defect]. Enable this checkbox to allow all users belonging to this group to be able to delete defects.

Note: Remember that any permissions you apply on a group level are going to affect all users in that group. If you don't intend for this consequence, then move the user to a different group / create a new group with the exact permissions desired and then move the user to that group.

2. Second Solution:

You can do this with some programming using both the QC Site Admin API and the QC OTA API.
It will go like this:
- Get all projects through the site admin API
- Connect to each project using the OTA API
- For each group in the project, remove the delete permissions using the OTA API

You will find a lot of help on the HP forums ( http://forums11.itrc.hp.com/service/forums/categoryhome.do?categoryId=895 ).

3. Third Solution :

1. You can give project administrator permission to all projects from site administration.
2. You can create a group as a copy of QATester group and add the delete permission to it and add this user to the new group in each project.

Unfortunatelly QC doesn't have yet many administration control feature that can ease you job here...
Unless you have Premier edition and all you project are connected to a template but then again you would have to accept a template change in each and every project.

 4. Fourth Solution: 

You can ask your DBA to write a query to delete the particular record and run the same for all the project schemas for which you want to delete.

5. Fifth Solution:

You can easily write a QTP Script to perform this task for you. Also the built in Admin user does have a password so you can log in with it, this account has full rights. The default password used to be tdtdtd . Oddly enough that is also the password to open up the VB code behind the Excel macro used to upload test scripts.