I have a possible fix in mind but to test it, you need to download Process Explorer,
Process Explorer is a better version of Windows Task Manager that i personally use too.
Download it, run it and look if you get near 100% (e.g 97%) of usage in "Hardware Interrupts and DPCs". If not, then look for other process that hogs all the disk resources.
Oh, is the drive in question a HDD or SSD?