Now that support for Windows 7 is over, a reader is ready to upgrade:

I have been a bit lazy so far to upgrade to Win 10 because I’m bothered whether or not I will have to reinstall all the programs which I downloaded before or will they be kept?

They said that documents, photos, etc won’t be affected but what about the rest. I guess it will only be partition C:\ which will be concerned?”

As long as you choose an upgrade and not a clean installation, your programs and files should be unaffected. That being said, you should always back everything up before doing any big change on your PC. (You should always have everything backed up anyway.)  Programs should be unaffected overall. Most programs that work with Windows 7 will work with Windows 10 but not all. Also, programs like Games and Media Center (not Media Player) that are part of Windows 7 will be overwritten by Windows 10.

The update will only affect the hard drive that’s running your operating system. That’s normally the C drive but it can vary from PC to PC. It can’t hurt to unplug your external drives during the upgrade.