• Launch Steam and start Counter-Strike: Global Offensive
  
• From the main menu select Help & Options
  
• Select the Game Settings menu item
  
• Click the arrow next to Enable Developer Console (~) so that it says Yes
  
• Click Back
  
• Once the developer's console option is enabled you will be able to use the ~ key to open the developer's console and type in commands to change game settings.

Enabling raw input can be one of the problems that can fix the mouse stuttering and stopping while looking around in-game. Type or copy and paste these comands into the developer console.

• Enable raw input mouse - m_rawinput 1
  
• Disable raw mouse input - m_rawinput 0

Mouse acceleration can also be a problem that cause the mouse to stutter and stop. Disabling mouse acceleration can help or stop all together the input lag that you are getting with you mouse as mouse acceleration makes the cursor move faster as it moves across the screen.

• Disable mouse acceleration - m_mousespeed 0
  
• Enable mouse acceleration - m_mousespeed 1

Having V-Sync (Vertical sync) enabled in CSGO or any game mean that your computer will try to synchronise the frame rate of the game with your monitors refresh rate to provide a better stability within the game, this makes the game look smoother but doesn't always make the game play better. If you disable the V-Sync within CSGO you'll essentially unlock the frame rate cap and along with that get screen tearing, but by disabling this feature you can stop input lag from occuring in some cases.

To disable V-Sync go into Steam and open up CSGO, once started up go into to
Settings>Video Settings>V-Sync>Disable like shown in the screenshot below.

One way that in some rare cases can fix keyboard input lag is changing the repeat rate and the repeat delay of the keys through control panel.

To do this open up control panel and search "Keyboard" in the settings search bar as shown.













Click on the the thumbnail that says "Keyboard" and adjust the repeat rate and the repeat delay settings to match that in the image below, save the settings by clicky "Apply" and it might be fixed.

One of the problems that can effect both the mouse and keyboard input in CSGO is the computer turning off the device automaticlly to save power. This normally shouldn't affect the mouse or the keyboard on your PC as this setting is turned on by default but sometimes it can.

To fix this problem you will need to search for "Device manager" in the start menu. Once you have finished typing there should be a program called "Device manager" showing in the results, open it up and if prompted allow any administrative privileges













Once you've opened device manager double click on the "Universal serial bus controllers" tab to open it. You should now have multiple USB ports listed.













Next right click on the first "USB Root Hub" and click on properties.














You should now have a window open that looks like this.



















Click on the "Power management" tab and untick the box that says "Allow the computer to turn of this device to save power"


















Repeat this for all of the USB Root Hubs that are listed on device manager to hopefully fix it.