Acer 5733 series, Win7 Home Premium, Model: PEW71

This laptop started as my mom's, then my brother's, now mine. It is running grossly slow. I'm going to reformat the whole thing and wipe the disk.
Question 1: Can I upgrade the OS to something newer and still get great speed?
Question 2: What OS is the most stable that I can upgrade on this laptop?
Question 3: There is no disk for Windows 7 Home Premium that I could use to clean the drive, although, the product key sticker is on the bottom of the unit. Now what? Can I upgrade using that key?
Question 4: Since this is an old unit (built 01-25-2012), is it possible to get upgrades for free?

Accepted answers

All comments

MaClane

Good night Charmie91752 !

First, which EXACT notebook model?
Example: ACER Aspire 5733-6666
I need the correct information to evaluate the hardware.

Answer to question 1:
To inform correctly, I need to know the right model.
Answer to question 2:
The same answer.
Answer to question 3:
You can download an original ISO from Microsoft's own website.
As for the lynch, it is OEM and exclusive and only for that version of the Windwo 7 home Premium that is installed.
Answer to question 4:
What kind of updates are you referring to?
If it is from Windows, it will update normally being original.