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Legacy Update Help

“There is not enough disk space” when installing Windows XP Service Pack 3

When installing Windows XP Service Pack 3 on a computer that is using hybrid GPT and MBR partitioning, you may receive the following error message:

There is not enough disk space on C:\WINDOWS\$NtServicePackUninstall$ to install Service Pack 3. Setup requires a minimum of 4 additional megabytes of free space or if you also want to archive the files for uninstallation, Setup requires 4 additional megabytes of free space. Free additional space on your hard disk and then try again.

When Service Pack 3 is installed through Legacy Update, this error will appear as “Fatal error during installation. (1603)”.

This error happens when Windows XP is installed on an early Intel Mac using Boot Camp. This issue can be worked around with the following:

  1. Click Start → Run. Type in regedit and click OK.

  2. In the left sidebar, navigate to My Computer\HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup

  3. In the right pane, find BootDir. If you don’t see it, right-click → choose New → String Value, and enter BootDir as the name.

  4. Double-click BootDir. Delete any value that already exists. Enter C:\ and click OK.

Alternatively, paste the following into a fixsp3gpt.reg file and double-click it:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup]
"BootDir"="C:\"

If your Windows installation is not on drive C:, replace the drive letter accordingly.

You can now attempt to install Windows XP Service Pack 3 again.