So this started after Windows Update installed updates two days ago. When I open a program, either that process or the Antimalware Service Executable process skyrocket in disk usage, grinding everything to a halt. I've disabled the BITS, Superfetch, Windows Defender, and Windows Search services. As I'm typing this, Microsoft Compatibility Telemetry began randomly using 49% of my disk at 26.0 MB/s. Not sure why. My C: drive's average response time right now is anywhere between 450 ms and 4000 ms, the highest disk activity is coming from CompatTelRunner.exe at ~13,000,000 B/sec in the Resource Monitor. I opened Origin just to test and the Origin process immediately started using 50% of my disk, and took ~1 minute to open (compared to the instant opening I'm used to). I've run chkdsk and a few other hard drive health programs, the hard drive seems healthy enough. I've been looking for an answer for the past two days. Any ideas where I should go from here?