My Internet is 3x slower on my pc rather then other devices After I downloaded a uncompatible application

Assuming a branded PC

Win11 by default only installs critical security updates, unless you made the mistake of selecting “Get latest updates” which includes drivers.

See your laptop/PC makers support to update both bios and ALL drivers.

There should be a shortcut to that makers update utility on your system.

Then set Bios to defaults & Pwr to balanced. At the end of the day shutdown, do not leave in sleep.

Do NOT update from any other source inc Device Manager

Okay Look

I'm on Win11 And I downloaded a app GCC which was supposed to change the RGB lights in my pc however because my parts where incompatiblle with the application it caused excessive lag and my pc recieved 3x less internet To resolve the issue i used a DDU and Graphics Card was installed again ect

however the Internet is still 3x less and on other devices they are receiving more internet

also a side question
If I create a new account on Windows and Delete the Previous accounts then will there be any changes to the internet since this new internet depletion typa problem only started after i downloaded a incompatible app

If you feel that GCC has not been properly uninstalled, a common solution is to reinstall it and then uninstall it again. Have you tried this?

Creating a new account and deleting the one you were previously using can resolve issues related to user data.
If the performance issue on your PC is caused by user data problems, this approach can help fix it.

Creating a new account will not remove any applications, but the applications will start checking the new directory (C:\Users(new user name)) instead of the old one (C:\Users(old user name)).
This means you will be recognized as a "new user," and when launching applications for the first time on this new account, you may be prompted to sign in again.
For example, you may find yourself logged out of browsers like Edge or Chrome and need to log in again.

What do you mean by saying that Wi-Fi speeds differ depending on the account?
Does that mean the issue is specific to only one particular account?

on the account where i installed the GCC it was super laggy so i tried playing games on a different account however that account was laggy but not as laggy as the previous one

I deleted the account where i installed and my wifi Doubled in Speed However My Internet Speed is still nearly double of that on other devices, I dont know what to do

The most reliable method is to perform a clean installation of your PC. This will remove all applications and require the reinstallation of drivers, but it is an extremely effective approach.

One thing I’d like to confirm: is the “other device” connected via Wi-Fi rather than a wired LAN? There is a significant difference in speed between a wired LAN and Wi-Fi. A fair comparison can only be made if both are connected to the same Wi-Fi network.

Additionally, if your PC is old, the performance of its wireless LAN card may be inferior to that of newer devices, which could result in slower Wi-Fi speeds.

Please try Step 3, Step 4, and Step 7 on this site. I have solved network issues many times using these steps.