The O/S installed...is just one variable in system performance.
Hard drive space...RAM installed...programs installed...system components...are just the most obvious that I would consider. Laptop A made 6 years ago...is not comparable to Laptop B made 1 year ago. A system made by one OEM is not necessarily comparable to a system by another OEM, depending on the items I listed above.
<<I do not know how to do all the suggestions that is pinned in this fourm.>>
You should never...consider implementing all
the suggestions...that may be posted...in a forum where anyone can suggest or post anything. Not all have the same merit/substance.
There are at least two approaches you can take.
One...use Google to try to obtain data/information...about the seeming validity of any suggestion.
Two...you can review the statements, responses by others to suggestions, etc...for any member, at any time...just by reading a given topic all the way through. That's the method I use for determining who is knowledgeable, along with a "does that make sense" attitude
Once you have some idea of who may be able to assist you and who cannot...just post a topic in the appropriate forum and await some responses from the membership.
Just bear in mind...that attempting to troubleshoot a system which is not within view/arm's length...is not as easy as changing the channel on the TV
But the membership will try to assist you...to help, not hurt.