Windows 8.1 x64 notebook not using all 4GB memory

[vandidant]

This is a Thinkpad Yoga S1 with i5 4200u and HD4400. At around 3GB usage, Windows gives me the memory low warning and then everything starts crashing. Why is it not using the entire 4GB? If it is occupied by integrated graphics memory, how can I reduce that allocation if that specific setting cannot be found in BIOS?

 

Another unrelated question: Windows 7 idled at 600 or 700MB, why is Windows 8.1 barely able to start with 1000MB even though Microsoft mistakenly removed the code for Aero?

[Bonesy]

Make sure you are using a 64-bit version of windows 8.1. If it is 32-bit, you are limited to 3GB of RAM. Do a search in your charms menu for "PC Info" It will tell you what you're currently using.(32-bit or 64-bit)

 

EDIT: Just saw you put x64 in title(oops)

 

I would then double-check the OS is correctly seeing and using your memory, please do the following:

Open command prompt and type in "msconfig" - this will bring up the system config window, move to the "Boot" tab, and select advanced options. On the top right you will see an option for Maximum memory. If this box is unchecked and has a value of "0", please check this box, and replace the 0 with 4096. Click Apply, then reboot your computer.

[Aniallation]

This is a Thinkpad Yoga S1 with i5 4200u and HD4400. At around 3GB usage, Windows gives me the memory low warning and then everything starts crashing. Why is it not using the entire 4GB? If it is occupied by integrated graphics memory, how can I reduce that allocation if that specific setting cannot be found in BIOS?

Same here. This seems to be normal. My i5-4300U and HD4400 allocate 512MB to VRAM. With how bits/bytes work that leaves about 3.3-3.4GB left to use by the OS, and Windows will generally start whining when 90% of RAM is full.