I have been building a new desktop and have tried to salvage the Hard Drive from my old build. My new computer currently has a Western Digital 70GB with 7200RPM and is a SATA 3.0, my old Hard Drive is a Western Digital 1TB with 7200RPM and is a SATA 3.0, so obviously I am confused as to why this doesn't work. The new one has Windows 7 Ultimate and the old one has Windows 7 Professional, the only major difference is the new one came in a HP, and the old one is in a Dell, but I couldn't imagine that making a difference. So anyway what happens is I take the new one out and put the old one in and start it up. The system starts up and then the windows logo comes up and begins to animate when it freezes. It then restarts on its own and starts up, but then gives me the start up failure message and asks if I want to start normally or in repair mode. The same thing happens when I put the new drive in the old build. Both hard drives still work in their original builds even after these attempts. Any Ideas?
Neither solution is legal, first off. Those are OEM copies of Windows and that means that you are only licensed to use them on the motherboards they were originally installed on.
There are very good technical reasons why what you are trying to do will not work as well.
When you install an operating system onto a computer, it configures itself for that particular hardware. If you then take that hard drive and put it into a different system, it is no longer configured correctly. Sometimes if the hardware is similar enough it may appear to work... but it will always work poorly.
Eventually your idea will fail anyway, once MS figures out that you have violated the license agreement.
Yes, and that is exactly what you would need to do.
Just be sure to reinstall the version of Windows attached to the Computer, not the Hard Drive.
You will also need to locate the proper license key for each instillation, usually found with a sticker on the case.
It would probably be a good idea to download all the drivers you will need to a USB stick before starting.
Just check on the support page for the manufacturer of your computer