I'm using Windows 8, 32 bits. It has a memory limitation of 4GB RAM on x86 systems. My PC has 6 GB of RAM. In order to bypass this limit, I have installed 3rd-party software called PatchPAE2 that lets me use all my RAM.
Is this software really working? If so, how can I be sure that my OS actually found 6 GB RAM and is actually letting me use my whole memory?
First thing you should know is: Use Windows 64 bits instead. As many comments state, you should install Windows 8 64 bits, because it has native support for up to 512 GB RAM, better memory support and management, better performance (for more memory setups), and you will be able to use 64 bit software, and not depend on 3rd-party solutions that could be a new possible source of bugs.
In order to inspect how much phisical installed memory your system possess, the easyes way in Windows 8 is to use either:
Press winkey and pause/break and check the "installed memory" value on the "System" section
Press CTRL, ALT and DELETE simultaneously. Click on the "Performance" tab and check for the "Memory" value.
A 32 bit operating system can address 2^32 bits, or roughly 4GB. The often quoted 3.25 - 3.5GB is an over simplification of how the rest of the computer and operating system allocate additional resources.
Physical Address Extension certainly does work, and has been used by various operating systems for years. Generally at the server level OS and not consumer.
With PatchPAE2, the software seems rather obscure. It is using concepts that should work from what I can gather, and there is a version for Windows 8.
As far as stability and ease of use goes though, I would personally opt for a true x64 operating system.
Run Resource Monitor of Windows to see if the RAM is fully used:
I used a bootloader to bypass the Memory Limit of 32Bit client Windows version and this works as you can see in the picture.
