I have a Dell Inspiron 5559 (4GB) with Windows 10 and Quickheal Antivirus installed in it. Everything is regularly updated. I often just shut the lid of the laptop without putting it into sleep or hibernation. The problem is the PC takes lot of time to come to the PIN screen. Secondly, while working on the laptop and using only Word, Excel, PDFs - it takes lot of time to swap between screens and there is a sustained lag many times while working. Furthermore, if I double click on any file in my Google drive or local drive it takes time to open and image files take a lot of time. When clicking on the windows button there is a lag in opening the menu or to open notepad. The laptop has 95% free space in its HDD. Looking for some advice on improving the performance of the laptop. Thanks!
My same model was running extremely slow for an i7 6th gen. In task manager my DISK would be running at 100% for a while after each boot-up and wake-up from sleep.
After coming across another forum the solution that worked for me was to update the intel RST (Rapid Storage Technology) driver direct from intel site. DELL-update would fail to pick this up and the one on the Dell support site was an older version than the one I had already installed.
I installed the SetupRST.exe file from the link above.
I have the same laptop and before my hard drive failed (it was an HDD), I was having plenty of slow down issues. If I am correct, the HDD on our laptops is considered to be bottlenecks. They drag the rest of the performance down. I ended up replacing it with a 1TB SSD from Sandisk and holy, the change is VERY noticeable in terms of startup and read/write speed. Instead of waiting normally 5 minutes to get completely loaded in, it takes 5 seconds from sleep and maybe a minute for the startup.
If you're curious, this is the one I purchased from Best Buy: https://www.amazon.com/SanDisk-Ultra-NAND-SATA-SDSSDH3-1T00-G25/dp/B071KGRXRG/ref=mp_s_a_1_fkmrnull_...
I have to warn you though if you decide to get this that you will not be able to use hibernation mode (or shouldn't as I guess I can shorten the life of your SSD and void any warranty if used).
It's the sad reality that this is probably your best solution overall, but if you don't want to spend money on another hard drive, you can upgrade your 4GB of ram to a max of 16GBs (two 8GB DDR3 sticks). You can view the listing for that here: https://www.crucial.com/usa/en/compatible-upgrade-for/Dell/inspiron-15-(5559)#MEMORYFilters
I upgraded both of these and it made a huge difference. If you have any more questions, feel free to reply. I suggest not opening up your laptop unless you're comfortable doing so and follow proper safety procedures to make sure you don't cause damage to yourself or the computer.