Question Laptop slowdown when/after trying to download big files.


Jun 20, 2019
Hi all,

I doubt I'll be able to find a solution for this but really hope I'm wrong. Short version is I got a new laptop just shy of two months ago as a gift. I don't have a receipt for it and don't want to trade it in so I need to resolve the problem.

It's an Asus X540L (I3-5005U, 4GB ram, 1TB HDD)

The machine turns very slow for no reason for hours. When playing video files in VLC everything is fine and then randomly the machine seems busy and it can't even play 480p video without freezing for several seconds to catch up. For example playing three seconds then waiting ten for buffering. Downloading from Steam the speed is maximum for my net connection for the first few minutes and then stutters crawling and peaks and lows later down to just 200kbps down from 6.5mbps. I can't be sure but downloading from the internet large files (several GB as a single file) seems to be a major trigger for the system slowing down.

An intermediate/advanced user I've been searching for a fix for many weeks online. I've done every fix for "100% disk usage" I can find online including disabling background services, anti-virus, windows defender, windows update, changing the page file, command prompt lines, scanning the hdd, even a full HDD wipe using an external USB to install windows. I've also disabled all indexing on the HDD to see if that helped. I've installed a more advanced third party task manager/monitor and there are no tasks using resources. I've even added desktop CPU and HDD temp monitoring tools and the temps are great at 38-45 on the HDD and around 50 on the CPU.

I wanted to try a theory since Steam downloads large files and went to the Internet Archive and downloaded one of it's legal torrents and got a 100% buffer overload warning from a torrent application (pre-allocation disabled) with its speed dropping to zero as it cleared the data backlog so it seems to be some kind of randomly occurring bottleneck with the HDD. I've replaced all system drivers manually with the latest version and no difference.

Right now I'm out of ideas. From disabling services to wiping windows itself I can't find the bottleneck causing random slowdowns and freezes. This is more than just a slow speed hard drive issue, I've had enough systems to know this really isn't normal. It's at the point now if audio is playing and it sticks I'll hear an audio glitch for a second before the system resumes functioning. Only other clue I have is when shutting down the system the screen will turn off as normal but it can take several minutes before all CPU/HDD activity ends and the machine is finally off.

(I have checked and disabled all task manager tasks, disk defrag tasks etc)

The only clue that it seems to be big file downloading related is that when the error hasn't occurred I can play Starcraft 2 and World of Warships quite happily. So I'm not sure how to fix this as for work downloading big files (I playtest games) is essential.