Maybe a monkey with a gun isn't the best avatar to install confidence in people :)
OK, your computer has two types of what people generally call memory. the one you stated is 180Gbytes is your hard drive, this is where your computer stores everything permanently on your computer such as all your pictures, videos, documents and also all the parts of windows required to make your computer run. when you turn your computer off everything on the hard drive is retained ready for when you turn the computer on next time.
You also have the RAM in your computer, the size of this is much smaller than your hard drive and it's only temporary storage, it's where your computer stores the information it is actually working on at any given time.
In your situation you do not have enough RAM in your computer to store everything it is working on at any one time so your computer is using some of your hard drive to offload some of the information it needs, this information on your hard drive is the virtual memory.
The main problem with virtual memory on your hard drive is it's 100s of times slower than your real memory so a lot of programes that run in the background on your computer insist on using a bit of your real memory, this makes you need for virtual memory increase. you can keep increasing your virtual memory but it will only slow your computer down as it needs to read info from the slow hard drive rather than the fast RAM.
The link I provided is from one of the largest memory manufacturers in the world and is perfectly safe. you don't need to buy from them, but you do need to know the correct sort of memory to buy if you want to solve your problem and that scanner will tell you that. (if you don't understand the result someone here will help you)