Black Candles are bearish lines in candlestick and candlevolume charts. They signify that the closing is lower than opening for that time period.
CHKDSK, short for Check Disk, is a utility that checks the integrity of the files and file structure of your hard disk. I'll walk you through it. I have disk problems and you said I should run CHKDSK. Great.
The easiest way to access the Disk Clean Up tool is opening My Computer (Start, My Computer), right-clicking on the drive you want to clean up and selecting Properties, General, then clicking on the Disk Cleanup button.