[SOLVED] Adding m.2 while having a HDD Installed already

[Spam Police]

Ok so i bought a prebuilt PC back in 2016 that was about 5 years old. Recently I upgraded everything except the case and the hard drive. So now I have a decent computer but whenever I have to load / download something it takes way too long and my disk is almost always at 100% Recently I have been thinking about buying a m.2 to speed it up a bit. I know my mother board is compatible (AsRock B450M Pro4) but will it work or tinker with my HDD. I'm sorry if this has a simple answer but when it comes to storage and stuff like this i'm completely clueless

(And by the way the Hard drive is a Western Digital blue 1TB not sure what exact model though)

 

[kerberos_20]

if u want m.2 just for better download speeds, then u just wasting money
any decent SATA SSD is cheaper than m.2 device, while it can offer up to 500MB speeds

 

[popatim]

Your download speed is mostly affected by your internet speed. What speed are you paying for? Run a speedtest.net and verify you are getting what you pay for.
You can divide the result by 10 for a quick approximation to convert from the MegaBits to MegaBytes which is what download speed displays as.
ex: if I see 51Mb/s on Speedtest then the most I might see on a download is 5.1MB/s

Then you are linited in how fast you can download by how fast the server you are downloading from will send it to you. I have 100Mb service yet the most I usually see is 5MB/s instead of about 10 for the max.

You can run a crystaldiskmark to check the speed of your HDD.
If its 5yrs old then I would expect to see anywhere form 20MB/s to 80, depending on how full it is.