RAM Extension

good

Its not more ram. But it make faster computer.
When ram dont use some files it put to pagefile.sys
its this what you making bigger. Optimal size of pagefile is 2xram
ex: 2x1024mb ram
you need 2048 mb ofpagefile.sys

Computer hardrive are extremely slow compared to ram.
If virtual memory (making some space on the hard drive available to running programs) can be useful when you lake main memory (RAM: Random Access Memory), it makes computer programs run very slowly. If you lake RAM, I would suggest you to buy some. 4 GB is not too much when running the latest game (at the date of comments)

this also known as virtual memory

will this harm my PC?

I tried this and it worked cool ;)

The Pagefile has nothing to do with RAM in terms of the amount of RAM you need for a specific task.
If a game requires 1gig of RAM and you only have 768Mb, setting the pagefile to 3gigs will not allow you to play the game..
However setting the pagefile to 3gig will increase speed and system stability, because windows will not run out of space when paging files it is using, therefore it won't have to keep re-accessing / re-paging information as it uses it.
Try setting your total pagefile size to 20mb and see how long your pc can cope with normal usage before it bluescreens or simply restarts

OK so i forgot to write in the video that this isn't the real ram memmory so some of you misunderstood and that the virtual memory works times slower than ram memory but i thought this is known sry :D ...........the poster of this video

no Ozzyviking i'm the one who posted this video and I didn't write that comment

Conclusion : you can encrase pagefile but not so much in not help better buy more ram ^^

yes you can increase PAGEFILE to lets say 2gb but your computer will work very slow. It's common knowledge that pagefile is goddamn slower than physical RAM!
Yeah try to run f.e.a.r. on 128mb physical RAM and 2gb pagefile Hahahaha lol
(If it will ever run, i bet windows crash faster than you can think )