Why is my Core i7 Lenovo laptop so slow?

I don't think the problem here is with your processor speed, since downloading a file places very small load on the processor. (By the way, if you open "Windows task manager" you can have a glance at your processor load wile downloading!)

Usually, the most limiting parameter is the internet path between you and the server: the other sides internet upload speed, your download internet speed and the quality of the path in between.
If you're on a slow Wi-Fi network, that can also limit.

In rare cases, the writing speed to your hard drive can also be a limitation. (If you're writing to a different unit over the Wi-Fi network, then you'll be competing with yourself for Wi-Fi capacity, since the file needs to get from the router to your computer and then from your computer back to the router and finally reach the storage unit…

No problem with your i7. Check your internet speed.

Download speed is dependant on the speed of your internet. Not the processor.

I think your internet is slow
please update your internet speed

Wrong setup? Background running apps?

As already mentioned, this has nothing to do with your CPU or the computer at all. It has everything to do with your network and internet connection.

It may not be your laptop, it sounds like you have slow internet speeds. Or the host server having slow access speeds can also slow downloads.

It is may not a fail of your laptop. Please run speed test software like internet speed. Install advance system care it will speed up internet. Also install IDM to speed up downloads

It could be problem on server. You can't receive more than server can send to you.

See all of above; a good analogy is having bought a Farrari (Core i7) you stuck in a traffic jam (Internet traffic) you aren t going anywhere even with that horsepower.