During an upgrade installation of Windows XP, you receive:

An error occurred copying file cdrom.sys to C:\$win_nt$.~bt\cdrom.sys. The file is missing.

To fix this problem:

1. Copy C:\Config.sys to C:\Config.sav.

2. Open C:\Config.sys in Notepad.

3. Press CTRL+A and press the Delete key.

4. Save the empty C:\Config.sys file.

5. Copy C:\Autoexec.bat to C:\Autoexec.sav.

6. Open C:\Autoexec.bat in Notepad.

7. Press CTRL+A and press the Delete key.

8. Save the empty C:\Autoexec.bat file.

9. Restart the Windows XP setup program.