To install or reinstall Windows 95 from the CD-ROM, the key on the sleeve of the CD-ROM is required. REGEDIT can be used to retrieve this key from the Registry, but is easier with the System Properties applet in Control Panel.
Editing the Registry should be done only by experienced users and with extreme care and the Registry should always be exported or backed up before any changes are made.
1. Start the REGEDIT.EXE program.
2. Go to the key HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Current Version\ProductId
The key contains a numeric string with groups of five, three, seven, and five digits. The three and seven digit groups are the CD-ROM key.
If you are using Microsoft Plus!, there will be also a key for the CD-ROM key of Microsoft Plus!.
Many users simply write the CD-ROM key directly onto the label side of the CD_ ROM itself, using a felt-tip marker. This practice might not be safe, since there is always a change that the solvents in the marker's ink could damage the surface of the CD-ROM over time.