So I built a new PC including a new HDD and a 250GB SSD. I added the old HDD too. I moved all my personal data (programs and settings etc excluded) to the new HDD and then reset my old HDD so there would only be Windows 10 there. Now what I wanted to do is get Win10 on my SSD by using Clonezilla which didn't work since my SSD is smaller than the HDD where it was installed. Creating a smaller partition on the old HDD did not work unfortunately. So I decided to just use an old USB drive with Win7 on it and then upgrade once installed. First, I tried booting from the USB drive and I got the error after clicking "Install now" - "A required CD/DVD driver is missing". So what I did was boot the PC as usual and start the setup from Windows Explorer. This solved the first problem but added a new one: "windows is unable to install to the selected location error 0x80300024". I did some reading and eventually decided to format the old HDD along with Windows (big mistake) and unplug all other hard drives so it would work. I will probably never know if this solved the issue since I'm now back again stuck at the "CD driver is missing" error since I can only boot from the USB drive and not launch in the explorer... Things I've tried: - After getting the error, plugging the USB drive somewhere else and try again - Change AIHC (or similar) to something else - Disable all USB 3.0 slots Nothing worked. Please help, I've been trying for hours!