If I clone a Hard Drive, Will I Have to Install an OS on it and All the Programs?

"Nope. By definition, cloning is making an exact copy. So if you're really cloning, reinstallation of the OS and programs should not be necessary.

See Wikipedia on disk cloning."

In general, disk cloning creates an exact copy of the hard drive, so reinstallation of the OS and applications is not neccessary.

"I can tell you from experience (just did this yesterday) that not all programs will work and may need a fresh install and reactivation.

I used Acronis to clone one HDD to another HDD. The cloning process went well. After the cloning I removed the original HDD and replaced it with the new HDD. The system booted up fine (using Win 7) and most programs worked fine. (All Microsoft programs worked) but some other (but not all) programs did not work and required that I reinstall and re-activate.

I contacted Acronis about this and their tech support people said that it is a native Windows function to detect a new drive and modify the registry. Depending on how the target program is written, this may require a re-install and re-activation.

So far I have found three programs that required this process. I did not lose any data in the process (all data files were saved) and everything went well.

So the direct answer is ""yes"" a clone makes an exact copy but ""no"" because the OS detects the change and modifies the registry. If the target program looks at the registry it can require a re-install.

Bill"