My hard drive letter is F:, and I want to change it to C:, how would i do this?

When I go into disk management it says windows can not change the drive letter of this boot or volume.

Rex, NT [2k / xp] will let you assign drive letters. But messing with C: is usually a BAD IDEA. That msg is trying to save you from yourself. M2

Drive C: is your primary drive where your system resides. You cannot change your drive to C:. As mechanox says " the system is saving you from yourself" Once I thought I was wrong, now I'm not so sure!

But sometimes XP install looses it brains and assigns the system drive to a letter other than c:. Here is a procedure to change that http://www.petri.co.il/change_system_drive_letter_in_windows_xp.htm

Yes you can according to Microsoft HOW TO: Change the System/Boot Drive Letter in Windows The information in this article applies to: Microsoft Windows 2000 Server Microsoft Windows 2000 Advanced Server Microsoft Windows 2000 Professional Microsoft Windows 2000 Datacenter Server This article was previously published under Q223188 IN THIS TASK SUMMARY Changing the System/Boot Drive Letter IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base: 256986 <http://support.microsoft.com/default.aspx?scid=kb;EN-US;256986> Description of the Microsoft Windows Registry SUMMARY This article describes how to change the system or boot drive letter in Windows. For the most part, this is not recommended, especially if the drive letter is the same as when Windows was installed. The only time that you may want to do this is when the drive letters get changed without any user intervention. This may happen when you break a mirror volume or there is a drive configuration change. This should be a rare occurrence and you should change the drive letters back to match the initial installation. NOTE: Please be aware of the following issue related to drive letters: 249321 <http://support.microsoft.com/default.aspx?scid=kb;EN-US;249321> Unable to Log on if the Boot Partition Drive Letter Has Changed WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk. To change or swap drive letters on volumes that cannot otherwise be changed using the Disk Management snap-in, use the following steps. NOTE: In these steps, drive D refers to the (wrong) drive letter assigned to a volume, and drive C refers to the (new) drive letter you want to change to, or to assign to the volume. This procedure swaps drive letters for drives C and D. If you do not need to swap drive letters, simply name the \DosDevice\letter: value to any new drive letter not in use. back to the top Changing the System/Boot Drive Letter Make a full system backup of the computer and system state. Log on as an Administrator. Start Regedt32.exe. Go to the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices Click MountedDevices. On the Security menu, click Permissions. Check to make sure Administrators have full control. Change this back when you are finished with these steps. Quit Regedt32.exe, and then start Regedit.exe. Go to the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices Find the drive letter you want to change to (new). Look for "\DosDevices\C:". Right-click \DosDevices\C:, and then click Rename. NOTE: You must use Regedit instead of Regedt32 to rename this registry key. Rename it to an unused drive letter "\DosDevices\Z:". (This will free up drive letter C: to be used later.) Find the drive letter you want changed. Look for "\DosDevices\D:". Right-click \DosDevices\D:, and then click Rename. Rename it to the appropriate (new) drive letter "\DosDevices\C:". Click the value for \DosDevices\Z:, click Rename, and then name it back to "\DosDevices\D:". Quit Regedit, and then start Regedt32. Change the permissions back to the previous setting for Administrators (this should probably be Read Only). Restart the computer.