If your Windows computer crashes or freezes when it "wakes up" from sleep mode or hibernation, disabling power-saving mode should help solve the problem (but if you use laptop you need to plug in the AC Adapter more often).
To disable power-saving mode:
Start -> Control Panel -> (Hardware and Sound) -> Power options -> Change plan settings (on the right side of the selected power plan - Balanced or High Performance) -> Change Advanced settings -> Expand the hard disk power options, by clicking on the "+" next to Hard Disk.
Change the time listed under Turn Off Hard Disk After to Never. Do the same for the Sleep, Hibernate After options.
Computers get hot. Everything inside a computer generates heat, and heat can cause component instablility (RAM, CPU and etc.) and crash your PC.
If the computer case is too hot, check if all your fans are spinning properly (you know by listening closely: do they make a sound?). Make sure that all of your computer's vents, grates and filters are unhindered by dust, pet hair, and other materials that prevent proper airflow. If you find any problematic areas, use a can of compressed air to clear the airways.
If you use a laptop, make sure to place it on a hard, flat surface that won't "smother" the chassis around its vents, thus restricting airflow.
Note: Be very careful while you are cleaning your computer because it is possible that you detach something (usually the SATA cables in desktop-computer cases are prone to detatching). Double-check everything before you turn your computer back on.
When you install and uninstall programs or when you move files, you leave behind leftovers known as fragmented files. Fragmented files can slow your computer down and cause a system crash especially if a program becoms unresponsive.
When your computer crashes and you see the following line: STOP 0x000000EA (THREAD_STUCK_IN_DEVICE_DRIVER), the video card driver is stuck waiting for something (usually a hardware operation) to happen. Most of you have probably seen nv4_disp.sys associated with this blue screen.
Updating the video card driver is one of the solutions to this problem. Before you download the latest driver check the model of your video (VGA) card (Nvidia or ATI Radeon).
Nvidia - click here to find the appropriate driver
ATI Radeon - click here to find the appropriate driver
Enter the exact model of your video card (which you can find in Start -> All programs -> Accessories -> System tools -> System Information or type System Information in the start menu search box -> Components -> Display) -> select the Windows version you use (Windows 7/8(.1)/10 32-bit or 64-bit) and download the driver.
After that, run the installer and follow the instructions. Reboot your computer if needed.
Note: If you don't know which Windows version you use and the system type (32-bit or 64-bit), right-click My Computer (This PC) and select Properties.
Some computers have only on-board video card driver (eg. Intel HD Graphics) and to update it you need to visit your motherboard manufacturer's website (which you can also find in System Information -> System Summary).