There is a problem with my shift, alt, and ctrl keys.

Hello,

Welcome to Microsoft Community.

Let me work with you to solve the problem of keyboard key combinations not working.

Does this only happen when running Roblox games?

Can you use these keys properly on other page? If they work properly on other page, then you can rule out a system problem.

In addition，Please try to perform a clean boot in Windows, so that you can determine whether a Third-party software program is interfering with your game or program.

How to perform a clean boot

1. Sign in to the computer as an administrator. If you are unsure if your account has administrator rights, see Create a local user or administrator account in Windows to find out how to see if your account has administrator rights, and grant them to your account, if necessary.
   
2. Select Search , type msconfig , and then select System Configuration from the list of results.
   
3. On the Services tab of System Configuration, select Hide all Microsoft services, and then select Disable all. Select Apply.
   
4. On the Startup tab of System Configuration, select Open Task Manager.
   
5. On the Startup tab in Task Manager, for each Enabled startup item, select the item and then select Disable. (Keep track of which items have been Disabled. You will need to know this later.)
   
6. Close Task Manager.
   
7. On the Startup tab of System Configuration, select OK. When you restart the computer, it will be in a clean boot environment. You can click How to perform a clean boot in Windows for more details about clean boot.
   

Disclaimer: A “clean boot” starts Windows with a minimal set of drivers and startup programs. It helps to determine whether a background program is interfering with your game or program and to isolate the cause of a problem.

These steps of "clean boot" might look complicated at first glance. However, to avoid any trouble for you, please follow them in order and step-by step so that it will help you get you back on track.

Best Regards,

Lenka-MSFT| Microsoft Community Support Specialist

First I will suggest Clean all temporary and junk files from your system:

Press the Windows key + R and a Run dialog box will appear Then type: temp
Press Enter to select all (by pressing Ctrl + A) from the open window and delete permanently (by pressing the Shift + Delete button)

Next: type: %temp% and Press Enter Select all (by pressing Ctrl + A) from the open window and delete permanently (by pressing the Shift + Delete button)

Next: type: recent and Press Enter Select all (by pressing Ctrl + A) from the open window and delete permanently (by pressing the Shift + Delete button)

Next: type: prefetch and Press Enter Select all (by pressing Ctrl + A) from the open window and delete permanently (by pressing the Shift + Delete button)

Note: Just skip the Files and folders which will not be deleted.

KatieBooty, by "entire computer freezes" do you really mean you can't use the computer by pressing any keys on keyboard (like pressing Windows key to try showing the start screen, pressing Ctrl+Alt+Del to open Task Manager), or just the games fall into login
loop indefinitely? Those are different.

Hello and thanks for answering ! The down arrow doesn't combine with several keys like the left and right arrows while pressing at the same time and the left shift and right alt key as well as the tab key. There might be some more keys but I haven't tested all. And most of the keys still works normally with the down arrow key.

It started to happen 3 days ago. There was no hardware component update or the game that received an update before this started to happen. I've done some moddings to the game recently during the period this problem started.

I tried disabling startup apps but it didn't solve my problem.

Or try the InPrivate or Incognito browsing (that will work around cache and cookies)

For FireFox, IE and Edge use Ctrl+Shift+P in the browser, for Chrome use Ctrl+Shift+N

Let us know the results