Without the word bootable, the answer would be a no-brainer. You’d simply copy all of the files and folders on the disc into a .zip archive file. Then, when you needed them on disc, you’d copy them back.
The problem, of course, is that the new disc wouldn’t be bootable. Not good with a Windows or Linux disc.
So instead, create an .iso file. This is basically an image backup of an optical disc–a compressed record of every bit on the CD or DVD. When you restore it, you make an exact copy of the original, including its ability to boot a PC.
Windows 7 can natively read an .iso file and burn a disc from it. Older Windows versions need third-party software. Active@ ISO Burner is quite good and free.
But to create an .iso file, I recommend another free program: ISO Recorder. Note, when you download it, that there are separate versions for 32- and 64-bit Windows.
By the way, ISO Recorder also works as an .iso burner. You can use it to burn the file back into a disc.
Read the original forum discussion.
Contributing Editor Lincoln Spector writes about technology and cinema. Email your tech questions to him at answer@pcworld.com, or post them to a community of helpful folks on the PCW Answer Line forum. Follow Lincoln on Twitter, or subscribe to the Answer Line newsletter, e-mailed weekly.