One simple workaround is
1. If you have more than one hard drive (I have 6 for example) disconnect all but c.
2. Boot into safe mode, print this off you can do no harm
https://www.howtogeek.com/107511/how...-the-easy-way/
when in safe mode just hit power restart it will then boot normally
If that does not work print this off
https://www.google.com/search?q=Rebo...I5K4gQaR3JVg39
I doubt it a lot but very rarely C may not be seen in the BIOS and may need to be reset, DON'T play with the BIOS unless you know what version you have and know what uyou are doing, it is dead easy really but can scare some