Try the following steps:
- Press "Windows Key + Pause Break" and look for "Installed memory (RAM)" and remember the value
- Click "Advanced system settings" located on the tab
- Click "Settings..." in "Advanced" tab
- Click "Advanced" once again and hit "Change..."
- Untick "Automatically manage paging file size for all drivers" if checked
- Select drive where OS is installed and tick "Custom size"
- "Initial size (MB)" should be set to the current bytes of RAM installed (eg. 8 GB of RAM makes 8000 MB, etc...)
- "Maximum size (MB)" should be set to the current maximum bytes of RAM installed (eg. 8 GB of RAM is exactly 8192 MB)
Calculations are easy, let's pick up 512 MB and multiply by 2. You get 1024, 2048 and so on until you get the value needed.