Ignore this advice
Certain checks are reaching a critical threshold.
The operating system is installed on a (slow) hard disk drive.
If possible, replace the hard disk drive by a much faster solid state drive (SSD).
Certain checks have exceeded a critical threshold.
The available space on the primary disk drive is only 4 percent.
You can clean up the disk drive (right-click the Windows Start button > Explorer > right-click the disk drive > Properties > Clean up) or you may want to remove unrequired files/folders, remove unrequired software or move data to an additional (internal or external) disk drive.