But be cautious is your are to use different HDs for each OS, last time that I'm tried Linux, some distros always install the boot manager in the HDA 0, ignoring the bios/uefi boot secuence and without giving any option to select where your like the boot manager, so the only option to avoid it, is to physically disconnect the HD.

Note: This has been a year ago, and I don't remember with watch distros happen this, only that one is of the bigs. Maybe has been fixed since them.

do explain. i thought GOG supports Ubuntu and Mint?

Ubuntu is a slow mess, and even installing it as a dual-boot on the hard disk (with the boot manager being installed on a separate flash drive) proved to be a pain. There are other Linux distros that are faster, but I don't know what's a distro that'll be perfect with me.

Apart from Android if you want to count it as a heavily modified Linux distro (it uses the Linux kernel).

disk compression tech and software have been around for ages. AFAIK they slow down performance and cause many games to fail. so why Win 10 if you actually play games???

Eh, Ubuntu is fine, the problem is it installs a load of crap that you don't need, kinda like windows. ;P

I looked in the specs, and android is pretty much a nerfed Ubuntu. more like a cellphone/tablet version of Ubuntu.

Problem is with Windows updates it gradually becomes slower, someone did a test once timing boot up from a clean install and then after some updates, suffice to say the results weren't pretty, add to that software like AV and drivers that have to load too and things will slow down a lot.
Reinstalling the OS will speed it up for a while but to be honest your laptop hardly wasn't a hot rod even 4 years ago.
If you want my advice, see if it's worthwhile to upgrade to a SSD, this will make a significant and lasting difference.

The 'crap' is not a problem for me. Plus I don't see what's the crap that I don't need in Windows. The problem is again, the installation is being a toughie and the distro itself is slow when compared to others.
And its the best fork or flavor of Linux you'll ever find. I'd install it on my PCs over Ubuntu anyday. You'll end up sacrificing the traditional Linux apps for Android apps, which are more than pure Linux apps to begin with.

a. Get rid of all the software you don't need it.
b. Use Sysinternals Autoruns or Comodo KillSwitch to manage what's starting with the system. (You will need to know what you're doing..)
c. Use MyDefrag (the site has taken down just a two weeks ago.. but you may still get it from backup
d. (optional) give Process Lasso a try. You'll be fine with the free version.

As for linux, get a minimal .iso/network installer, burn it/make usb and install whatever you want. And/or check adamhm's The Big "Try Linux" GOG Game Giveaway

edit
In case you decide to do a fresh install of Win7, use WSUS Offline Update for updates, this way your OS will be cleaner and updates will install a way faster than traditional way.

hmmm... have you tried to point with a loaded gun at that old bastard :)

well..

That sounds like hearsay. Just googling now, Tom's did a test on an SSD, and the read speeds were about the same and writes suffered a little. I haven't yet been able to able to find a benchmark for an HDD, but I did find someone who posted that compression speeded up reading large text files significantly.

Far as I know Windows 10 can compress the OS separately from everything else, so when it comes to the likes of reading the disk while booting that could have an effect.

Edit: Also, I remember reading that an update to Windows 10 enables memory compression, that is, instead of swapping data out, compressing it in memory then decompressing. When memory is tight that should help performance. (This kind of technology certainly helped Android in my experience.)

-buy more RAM;
-switch to SSD.

Personally I never suggest a format to those who say their PC is slow.

The first thing I suggest to Windows users is these 2 steps:

1. Remove any Malware/Adware in your PC with Spybot Search & Destroy and MalwareBytes Anti-Malware
2. Clean Junk files with CCleaner and System Ninja

The second thing is disable software that runs at startup (this is usually the main reason why the PC is slow):

I often bring computers and laptops in at my house for repairs, the one thing most of them have in common is programs that run at startup which these people don't even use. These programs not only consume ram and increase boot time but some of them may even have services installed which consume yet more ram.

--------------------

A few things to OP:

AVG is a piece of trash imo (aka resource hog), Avast is somewhat better both resources and detections wise.
You can remove the "Get Windows 10" nag screen but uninstalling update KB3035583
Do the things I mentioned above.

Optional: Get an SSD.