100% Disk Usage (OS or damaged hard drive?)


Jan 1, 2017
Hi guys,

Firstly I have checked the other threads that are similar to this, but I see enough to differences for me to feel I need to post up what I'm experiencing in order to get an accurate answer from you, the geniuses that solve all computer related issues on this forum.

So, I've got a two year old gaming PC, which I've recently opened up and replaced the graphics card. This is the first time I've ever replaced a component, or opened up my PC, so I was incredibly hesitant and nervous. I replaced a GTX 760 with a GTX 1070.

My build is as follows, if that's important (sorry, I'm a gamer, but useless with hardware!):

Aerocool Dead Silence All-Black Gaming Cube Case
Intel Core i5 4440 Haswell Processor 3.00 GHz (No Overclocking)
Intel Stock Cooler
Generic thermal paste
ASUS H81I-PLUS Mini ITX Motherboard
8GB PC3-10666 1333MHz DDR3 Memory (2 x 4GB sticks)
[strike]Chillblast NVIDIA GeForce GTX 760 2GB Graphics Card[/strike] Now MSI Gtx 1070
Seagate 1000GB SSHD Hybrid Drive
FSP Premium Grade 500W PSU
Windows 7 Home Premium 64 bit
Windows Optimisation Service
Standard Chillblast Cable Management
5 Year Warranty with 2 Years Collect and Return
Gigabyte M7 Thor Gaming Mouse
Zalman ZM-K400G Gaming Keyboard

I've followed all the options I could find on the internet, such as disabling superfetch and windows search, switching antiviruses and ensuring I have the latest drivers.

I don't think it's a compatibility issue with my new graphics card, and can't see how that'd effect disk usage... The card itself runs fine, and I can now play Witcher 3 on Ultra.

The reason I suggest it might be hard drive damage is if I knocked the hard drive at all when putting in the graphics card. I had to remove all cables to get the card in, because of some bad wiring.

I had Windows 10 prior to installing the new card, and it never had any issues running.

The main noticeable issue the 100% disk usage is causing is on startup, as my PC now boots up a lot slower than it did prior to the graphics card change.

If I've missed something (sorry, was in a rush to get this out) just buzz and I'll add any additional info that I can.

Many thanks!


Knocking drive while installing GPU is unlikely to cause this, more likely to hurt card than drive itself

are you on 10 or 7? you tagged post as 10 but listed 7 in the info?

Do you have all the windows updates? See if this helps: http://www.tomshardware.com/faq/id-3267507/fix-100-disc-usage-system-service.html

Did you reinstall GPU drivers after updating card? Just wonder if slowdown is caused by PC waiting for GPU drivers to reply, though you say it works fine.

Can you go to task manager/performance tab and open resource monitor
look in the hdd description on the summary page and sort by read or writes and see which is using most. you can expand the file column so it shows file names. Then either tell us names or google them, and we see if there are easy answers :)

you can run Seatools for windows on the sshd and see what it shows.


Jan 1, 2017

Hi Colif, thanks for your help!

I am on Windows 10, the specs I posted up are just from the initial email of the PC build I ordered, I didn't build it myself haha. I've had Windows 10 since it was first rolled out to users of Windows 7 and 8, and have had no problems up until I changed the GPU.

I followed the link and the steps listed, no change in disk usage.

One thing I didn't do when installing my GPU was to uninstall old graphics drivers and then reinstall new ones. However, I got a more tech savvy friend to use a software which stripped the drivers from my PC, and then re-installed the drivers again after inserting the new GPU. Like I said, games run fine so i don't think that's the issue.

Went to task manager/performance on bootup, which is one of the slowest periods of the PC. Generally, it'll sit on 100% disk usage for about five minutes after it's all booted and I'm on my desktop, able to access programmes. Everything runs really slow for those five minutes, then things become smooth again and the disk usage goes down, sporadically picking back up to 100% for no obvious reason.

Here's the screenshot

Tried Seatools for windows, but not sure which test to run? I tried the SMART one, no issues identified.



Graphics: Okay, sounds like friend ran ddu which is what I would have suggested anyway

I would have thought an sshd could load windows faster than that, how much free space do you have on the drive?

Some advice i read was to turn on virtualisation but that won't work on an I5 as they don't have it anyway.

I can't figure out what UNistack is for. This advice might help, though you done some of it already: https://www.drivereasy.com/knowledge/fix-100-disk-usage-in-task-manager-improve-pc-performance-on-windows-10/