agiro,

Your computer has been verified by Dell to run Windows 10. Meaning that Dell has created Windows 10 drivers for the Inspiron 5521. Windows 10 is still having some issues on computers but, updates are being downloaded to correct theses issues.. You can reinstall Windows 10 if you want to do so. You can also click the links below for information on how to help with system performance. There is also a link to a google search for WIndows 10 slow/;laggy performance issues and ways to help.

Troubleshooting slow system performance

Windows 10 Slow/Laggy Performance issues

Thank you for your help.

I was told by the way that I should use drivers from dell.com including my AMD card's driver. However, that driver is a year old and I have recent software that run with issues when using the drivers from dell.com. I use drivers downloaded from amd.com instead (said to be compatible with my card).

Do you think this could cause the freezes during restart or shut down?

Just one more question to clarify, Sir, install the drivers from amd.com (latest) or the driver from dell.com/support by product?

agiro,

Try installing the Chipset drivers followed by the Intel HD drivers and then the AMD Radeon drivers. Reboot the computer after each driver install before moving on to the next. Hopefully, this will resolve it. 

Inspiron 5521 Drivers, Downloads and Manuals

agiro,

You can try the one from AMD to see if that will work. If the problem still persist you can install the one from Dell.