i'm using a windows 10 if that helps at all
There are a lot of things that can be a factor.
Your CPU speed can be a factor.
The number of cores it has and the number of things going on on the system will certainly have an effect.
The more processor or CPU performance being used by other stuff the less there is for the decompression software.
The drive usage is certainly going to play a factor. The more other software is accessing the drive the slower the decompression will be.
A system with two little memory will end up using drive as virtual ram far to often.
Or it could be something as simple as someone trying to watch a movie or use a program that is accessing the drive.
When it comes to drives. Windows is a bit of a shit. It almost never sets up accessing drives at their top speed. Take doing a file copy from drive A to B you have to.
A lot of devices like tablets are running slower CPUs because of power constraints and they have smaller and cheaper drives and are usually have to little ram.
Like Wyrmslayer70 said DL speed has nothing to do with decompression speed.
Pretty much any windows 10 device using less than 4Gigs is going to use up virtual memory. That means it will be using the HDD or SSD a lot more than it should. The more windows on browsers you have open the more apps you have open the worse it gets.
How filled up and fragmented the drive is is going to play a part also.
Use the windows task manager to see how much it happens. Unfortunately it also is going to add to that factor.
Because of the low ram numbers in tablets bad spots in the SSDs come up faster and more often. Thus those also mean maping around them for drives internal software.
You can increase the priority the program has but don't over do it.
You can try and set windows to maximize the drive potential. If you aren't used to doing it well you probably shouldn't you are more likely to cause harm than good and don't just download software thinking it will work.
Hope that gives you an idea of how hard it is to say what the specific issue is for you.