Laptop is having lagging trouble.

Hey!
I have 2 laptops, an old Lenovo and one new Asus with win 10 x64 installed. Old Lenovo is preinstalled OEM windows vista. Both the laptops have some very important files and to improve the cyber security of the systems, I have installed antivirus and antimalware softwares installed. In Asus I have Kaspersky Total Security 2017 as AntiVirus and MalwareBytes installed where as in vista laptop I have AVG free and MalwareBytes installed for protection from possible malware and virus. Both the laptops have similar applications installed, nothing too graphic or memory heavy. I use both of them in almost similarly, and connects to same WiFI network.
I have no issues with my Asus laptop, but Lenovo laptop is lagging too much than it’s normal performance. You can say it may be because of it’s age. But it worked perfectly fine until a couple of weeks back. What do you the problem can be, some sort of virus or malware issue or do you think some hardware trouble is on it’s way? With my little knowledge, I can’t identify any hardware issues. If it’s malware/virus trouble, does that mean AVG free is not doing it’s job?

Sorry for making it a bit confusing.
I will tell the details of the problematic laptop only:
Lenovo Y550
OEM Vista x64 Installed - which I am looking to upgrade into Win7 x64.
AV - AVG Free AM- MalwareBytes
4GB DDR3 Intel Core 2 Duo
Use a laptop cooler as well.

Use:
Movies, Music, Browsing, Blog Writing, HTML coding, Occasional Photo editing(only Jpeg) in lightroom, Occasional gaming (old games like Age of Empires and Rise of Nations) and other small things.

Lenovo though old, worked perfectly, until a few weeks back. Never showed any BSOD or overheating shutdown problem.
Now with this lag, I am concerned if it is a malware/virus trouble or worse, signs of deteriorating hardware. I want to confirm before making a Win 7 upgrade.

Thanks!

I'm going to have to do a little "Guessing" since You didn't post a few things. First off would be on the CPU/RAM. Looking at this Review http://www.notebookreview.com/notebo...d-y550-review/ You could be running a Core 2 Duo with 800 RAM or possibly a later Model https://www.newegg.com/Product/Produ...82E16834146612 with a P7459 with 1066 RAM ?? Giving Specs like those goes a long way.

If AVG and Malwarebytes don't show it's infected with Malware, You could stress test both the RAM and CPU. IF You're still running the Stock original Hard Drive I'd be inclined to think that might be the problem and suggest You check it first. Laptop 5400 RPM drives are really slow and an upgrade to a small SSD could possibly breathe new life into it provided the other components are good.