Windows detected a hard disk problem

I get this warning constantly all of the sudden about my secondary HDD that I store files on. I ran CHKDSK /f F: and came up with no errors found, yet I still get the warning everytime I start up and periodically during operating. Suggestions needed. :confused:



Also, ran the TSG sys utility that was sugessted here before posting and it reports Defender is disabled, yet Windows tells me its not. ???
I will run some various Malware scans but wondered if this is just an error with TSG and Win8.



Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 8 Pro, 64 bit
Processor: Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz, Intel64 Family 6 Model 58 Stepping 9
Processor Count: 8
RAM: 16344 Mb
Graphics Card: NVIDIA GeForce GTX 670, 2047 Mb
Hard Drives: C: Total - 237945 MB, Free - 145456 MB; F: Total - 1430796 MB, Free - 321938 MB;
Motherboard: Gigabyte Technology Co., Ltd., Z77X-UD5H
Antivirus: Windows Defender, Disabled