If you see this message Invalid system disk, Replace the disk and then press any key when you try to boot into Windows, here are a few troubleshooting suggestions you want to try.
This happens when you computer does not find a hard disk to boot from or hard disk displays no functioning operating system to boot from. Basically, if means that your Boot Disk or the Boot partition or the data could have been corrupted or damaged, which prevents your computer from booting normally.
Invalid System Disk
The exact error message is:
Invalid system disk, Replace the disk and then press any key. Reboot and select proper Boot device or Insert Boot Medua in selected Boot device and press a key.
If you receive this error, here are a few things you can try.
1] Boot into your BIOS settings and ensure that your Boot Disk is set as your first bootable device. You will see this setting under Advanced BIOS Features > Hard Disk Boot Priority.
Remember to Save the changes and exit. Changing the Boot order usually helps.
BIOS is a firmware. It is stored on a chip on a part of the computer motherboard and is basically, a set of instructions that run to help load the operating system.
2] Run ChkDsk on the Boot partition. You may have to boot your PC from an external media to do this.
3] Repair Master Boot Record using the Bootrec.exe tool and see if this helps.
4] Boot into Advanced Startup Options and then from Troubleshoot > Advanced options, select Automatic Repair.
If you cannot do this, you will have to boot from your Installation media. See this post if Automatic Repair fails.
Hope something here helps you. If you resolved the issue using another method, please do share here for the benefit of others.