Why is my HDD at 100% usage even when idle?

[Jacob999]

Recently, my drive usage his been practically stuck at 100%. After boot up my PC is fast, then after a few hours it suddenly slows, with my drive usage as the only culprit. It makes even simple browsing an absolute nightmare.

What could the cause be for this?

 

[ss202sl]

Indexing? Virus Scan? something's running - look what tasks or processes are running.

 

[SuperSoph_WD]

Hey there, @Jacob999!

I'd advise you backup all your data from the system somewhere off-site before proceeding with the troubleshooting of the drive. Better safe than sorry, right? Afterwards, check the processes in Task Manager or the Resource monitor. Make sure you scan for viruses and malware, as @ss202sl suggested. If turning off these Windows Services doesn't help, you should try swapping the SATA cable and the port where the HDD is connected on the motherboard.
If the poor performance and high disk usage is still present, I'd strongly recommend running your hard drive manufacturer's brand-specific diagnostic utility to check up on the health and SMART stats.

Hope these steps help you. Keep us posted!
SuperSoph_WD