HP Pavilion G6 1371EA running extremely slow

Apologies if this seems a bit prematurely but I would like to get ready before diagnosing the laptop.
My daughter’s laptop is running extremely slow, so slow I could not connect to it though TeamViewer. She will be bringing it to me on Sunday. I believe it has been updated from Windows 7 Home Premium to Windows 10 Home.
In readiness to Sunday I would like to know what to diagnose first and what other diagnostics I should be doing to establish what is causing it to be so slow.
Any help will be most appreciated.

Is the laptop just slow on the internet or is it slow all the time? For example when she clicks on anything it takes forever for that program or item to open? If it is slow all the time she might have a failing hard drive. The Seagate drives that HP puts in their laptops fail quite a bit. I replace a lot of them. There should be a hardware test that you can run on the laptop. If you can not find it then you can go to whoever the manufacturer of the hard drive is and download their free diagnostic tool. Run that and it will tell you if the drive is good or bad. That is where I would start. If it's just the internet that is slow then let us know and we can try other things.

scopio said:

The laptop is slow all the time not the internet connection.

Have ordered a WesternDigital WDS500G2B0A WD Blue 3D NAND Internal SSD 2.5 Inch SATA, 500 GB in anticipation.

You're on the right track. Definitely sounds like a failing hard drive.