How to speed up a slow laptop

[E9Luke]

I’m the family tech support guy, and my adult granddaughter has a slow laptop. It’s only two years old, but it has gotten very slow. It takes about five minutes to restart, for example, and web searches progress painfully slow.  Here’s what I’ve done so far—

• Checked for updates—all good. 
• Ran disk clean–up and dumped the stuff that typically appears in the results. 
• Scanned with MalwareBytes (found two PUPs, but nothing else).
• Checked for dodgy applications, but don’t see any. 
• Cleaned out her Outlook inbox—she never deletes anything, and I found 64K+ messages. All gone now, but produced no benefit. 
• Started to de fragment, but the system is set to defrag weekly. Fragmentation is at 1%.

Nothing I’ve done has helped. I’m thinking I should try resetting the OS without losing any data. My concern is that resetting will remove her precious video games. 

My questions for anyone here: How would you approach this situation, and how do I prepare this machine for a reset, if that’s what I need to do?

[banhien]

@E9Luke 

I can NOT find its official specs:  https://support.hp.com/au-en/product/product-specs/hp-15-dw0000-laptop-pc/model/34443600    Only:   https://www.amazon.com/HP-15-dw0083wm-Pentium-Windows-Renewed/dp/B0BS49SRR8

It is a slow machine at the beginning. It use slow CPU, only has 4GB of RAM and 128GB of storage.

1. CPU: you can NOT upgrade because it is integrated (soldered) to its system board.
2. RAM: It has 1 slot of RAM with One SODIMM memory module slot, non-customer-accessible/non-upgradable (Pentium and Celeron processors). But you may be able to replace 4GB with max 8GB DDR4 2400MHz RAM using Crucial 8GB
3. STORAGE: It has 128GB (I think it is M.2 SATA 128GB), after 2 years it may not much spare room therefore data has to find for space which caused the slow down of speed. You can upgraded to 1TB or 2TB of M.2 NVMe SSD using

                   Samsung 970 M.2 SSD

Note: I do not have its Official specs, for storage, I believe it has 128GB of M.2 SATA SSD but Crucial says other way. You can use Device manager to check

Regards.

[E9Luke]

Disk manager reports that this machine has a Western Digital WD5000LPLX-60ZNTTO DCM: EAOTJBB WX21E 500GB drive HDD. Yeah, it’s no flaming gaming machine, but it performed better back when it was new. It was less than $300 at Walmart. I want to keep it running as best it can. I very much appreciate your response.