Welcome to the forums, Serpico
I don't think you have a hardware issue, the problem you are describing points to driver &/or software corruption or incorrect settings. First off lets clean out your temporary files. There are 2 methods, (1) goto your root drive (usually (C)) and right click Properties on the general tab, and click "Disk Cleanup" after it finishes scanning (may take awhile) click (OK). . . OR method (2) (preferred) download the free version of cCleaner from
http://www.piriform.com/ccleaner/download , (this is a popular and trusted application used by many people, and considered a must have next to security software if your not familiar with it). It's a small file (less than 6mb). I personally don't use any of the bundled add-ons included, so uncheck them and install cCleaner only, or scroll on down to the bottom of page and select the "builds page" and dowload it from there (this one has no bundled software included). Install and run cCleaner at default settings (may take awhile). After running cCleaner while its still open, go down the left hand column and right click each of the choices there (except the last 2) that doesn't have a check mark (but don't add a check mark) and select "clean". This will clean each category manually. Next "IF" and only "IF" you don't have your OS installed to an SSD, defragment your OS Installed HardDiskDrive. SSD's don't require (nor recommended) defragnenting. Now your file system should be fairly clean and organized. The next thing to check is the settings within "Internet Options", goto "Control Panel" and select "Internet Options" (if you haven't choosen to install "cCleaner") on the general tab click "Delete" in the browsing history and put a check mark in all boxes except the first one "Preserve Favorites" and click "Delete", you can uncheck them after it runs if you like, and then click on the "Security" tab. Click to highlight the "Internet" icon and then down to "Custom Level" and click. Match the settings here to what your other working computer has set (the computer that has no download problems). Also do this for the "Trusted Sites" icon.
I'm going to stop for now and see if you have any improvement.
I'll check back later.
Another note, please provide your "PC Specs" so we can help you better.
🙂