I have a Toshiba Laptop (Satellite C850-B516) for which I need dual booting. I have already Windows 7 and Windows 8 installed. The first few days both worked fine, but now when I choose Windows 8, a message shows up says:
"Your PC ran into a problem and needs to restart. We're just collection some error info, and then we'll restart for you."
After restarting and choosing Windows 7, a black screen shows up and says:
"checking file system on D:...... one of your disks needs to be checked for consistency. " etc
What's the problem and how can I fix it?