A Registry key controls which users may format or eject removable hard disks in Windows. The key can be changed by administrators to give additional user groups the right to format or eject the hard drives.

Open the Registry by pressing Windows R, typing regedit and hitting enter. Navigate to the Registry key HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon and look for the string allocatedasd. The default value is 0 which means that only administrators may format or eject removable hard disks. If you want to change this you can set it to 1 to give the right to Power Users or to 2 to give the right to normal users as well.

Dasd sounds like a random string but it actually means Direct Access Storage Device. If you use Windows XP Professional you can also start gpedit.msc instead and navigate through Local Computer Policy > Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options and double-click the entry Devices: Allowed to format and eject removable media and change the setting from Administrators to the one that suits your needs.