Close Roblox completely
Open File Explorer
In the address bar, type `%localappdata%` and press Enter
Open the `Roblox` folder
Delete the `Cache` folder if it exists
Delete the `http` folder if it exists
Delete the `logs` folder if it exists
Open the Run box with `Win + R`
Type `%temp%` and press Enter
Delete any Roblox-related temporary files or folders
Empty the Recycle Bin
Restart your PC
Reopen Roblox
Update Roblox if prompted
Lower Roblox graphics settings if lag continues