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 open Disk Cleanup is to open the Charms bar and then click on Search. Type in Disk Cleanup and then click on Settings. Click on Free up disk space by deleting unnecessary files. This will bring up Disk Cleanup.