Be VERY cautious when following these steps, or you may inadvertently open up serious security holes -- there IS a reason Microsoft locks this folder down tightly.
1. Open a command prompt.
2. Type
XCOPY C:\WINDOWS\TASKS c:\TASKPERM /s /e /k /oThis will copy the tasks folder, in its entirety, including permissions and attributes. This essentially gives you a "mirrored" version of the scheduled tasks at C:\TASKPERM. It is probably not necessary to copy the tasks within the "Tasks" folder (the /S flag does this), but I like to be complete. :-)
3. Go to Windows Explorer and modify the ACL of C:\TASKPERM to suit your needs. Remember that if the user/group you are assigning permissions to should not be able to modify ALL tasks, it is important to set the "Apply To" attribute to "This folder only."
4. Back at the command prompt, type
CACLS C:\TASKPERM /SSelect the SDDL string (the stuff between the quotes) into the clipboard. Since the command prompt does not support line-wrapping text copy, you may have to post a larger string into notepad, and then trim out the stuff on either side of the quotes. You only want the bare SDDL string in the clipboard.
5. Type
CACLS C:\WINDOWS\TASKS /S:...replacing/pasting the
6. Test!
7. Delete the C:\TASKPERM folder.
Not too bad, right? If you screw up your C:\WINDOWS\TASKS folder, the default ACL for Windows Server 2003 is D:P(A;OICIIO;FA;;;CO)(A;;0x1200ab;;;BO)(A;;0x1200ab;;;SO)(A;OICI;FA;;;BA)(A;OICI;FA;;;SY)
Source: http://www.avianwaves.com/Blog/entryid/72/Easy-Way-to-Change-Permissions-on-the-Windows-Server-Scheduled-Tasks-Folder-C-Windows-Tasks-