USB Drive suddenly became read only

To reformat the drive do this:

Extended Hard Drive Preparation

1. Open Disk Utility in your Utilities folder.

2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.

3. Set the number of partitions from the drop down menu to one. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, set the partition scheme to GUID (only required for Intel Macs) then click on the OK button. Click on the Partition button and wait the process has completed.

4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.

5. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, check the button for Zero Data and click on OK to return to the Erase window.

6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.

I'm not sure why you were using that article to install Windows on the Mac. Perhaps you could explain what you were trying to accomplish. I hope you are also aware that Windows cannot be installed on an external drive nor boot from an external drive. If you are trying to run Windows on your Mac then see the following:

Windows on Intel Macs

There are presently several alternatives for running Windows on Intel Macs.

1. Install the Apple Boot Camp software. Purchase Windows XP w/Service Pak 2 or Vista. Follow instructions in the Boot Camp documentation on installation of Boot Camp, creating Driver CD, and installing Windows. Boot Camp enables you to boot the computer into OS X or Windows.

2. Parallels Desktop for Mac and Windows XP, Vista Business, or Vista Ultimate. Parallels is software virtualization that enables running Windows concurrently with OS X.

3. VM Fusionand Windows XP, Vista Business, or Vista Ultimate. VM Fusion is software virtualization that enables running Windows concurrently with OS X.

4. CrossOver which enables running many Windows applications without having to install Windows. The Windows applications can run concurrently with OS X.

5. VirtualBox is a new Open Source freeware virtual machine such as VM Fusion and Parallels that was developed by Solaris. It is not yet fully developed for the Mac - some features are not yet implemented - but it does work otherwise.

6. Last is Q. Q is a freeware emulator that is compatible with Intel Macs. It is much slower than the virtualization software, Parallels and VM Fusion.

Note that Parallels and VM Fusion can also run other operating systems such as Linux, Unix, OS/2, Solaris, etc. There are performance differences between dual-boot systems and virtualization. The latter tend to be a little slower (not much) and do not provide the video performance of the dual-boot system.

See MacTech.com's Virtualization Benchmarking for comparisons of Boot Camp, Parallels, and VM Fusion.

Boot Camp is only available with Leopard. The Boot Camp Beta that was used with Tiger has expired and is no longer available for use. So contrary to the other poster's comment, Boot Camp isn't truly "free." You must purchase Leopard to get it.

If the options are grayed out then you haven't selected the topmost drive entry, but you are selecting the volume sub-entry. You must select the topmost drive entry.

A missing driver error would suggest that you have other problems with your system or you are using a non-Apple optical drive. I suggest you reinstall OS X before trying to install Windows. I would start by first removing your Boot Camp partition using Boot Camp Assistant. Then try the following:

How to Perform an Archive and Install

An Archive and Install will NOT erase your hard drive, but you must have sufficient free space for a second OS X installation which could be from 3-9 GBs depending upon the version of OS X and selected installation options. The free space requirement is over and above normal free space requirements which should be at least 6-10 GBs. Read all the linked references carefully before proceeding.

1. Be sure to use Disk Utility first to repair the disk before performing the Archive and Install.

Repairing the Hard Drive and Permissions

Boot from your OS X Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Installer menu (Utilities menu for Tiger.) After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported, then quit DU and return to the installer.

2. Do not proceed with an Archive and Install if DU reports errors it cannot fix. In that case use Disk Warrior and/or TechTool Pro to repair the hard drive. If neither can repair the drive, then you will have to erase the drive and reinstall from scratch.

3. Boot from your OS X Installer disc. After the installer loads select your language and click on the Continue button. When you reach the screen to select a destination drive click once on the destination drive then click on the Option button. Select the Archive and Install option. You have an option to preserve users and network preferences. Only select this option if you are sure you have no corrupted files in your user accounts. Otherwise leave this option unchecked. Click on the OK button and continue with the OS X Installation.

4. Upon completion of the Archive and Install you will have a Previous System Folder in the root directory. You should retain the PSF until you are sure you do not need to manually transfer any items from the PSF to your newly installed system.

5. After moving any items you want to keep from the PSF you should delete it. You can back it up if you prefer, but you must delete it from the hard drive.

6. You can now download a Combo Updater directly from Apple's download site to update your new system to the desired version as well as install any security or other updates. You can also do this using Software Update.

As an addition to this Windows 7 is not supported on the Mac. There are no fully Windows 7 compatible drivers available. Some features will not work as-is. For now XP w/SP2 or Vista are supported. Boot Camp drivers are included on your OS X installer DVD.