“Error 633: The Modem is already in use or not configured properly.”
Solution
Error Causes
This error can be triggered due to several reasons such as:
- A software program conflicts with the USB modem
- The modem is not configured properly
- The Telephon.ini file is missing or damaged
- There is some issue with the way Windows is managing the communication (COM) ports on your computer.
Further Information and Manual Repair
If you experience the Modem Error 633 on your PC, you don’t have to panic. Though this error does not pose any major threats like data loss, it may hamper your ability to use the internet therefore it is advisable to resolve the error. Repairing the Modem Error 633 is quite easy. There are a number of ways to fix this error. So, let’s get started:Solution 1: Delete Incompatible Software and Non-Present Modems
- Click on the start menu and go to the ‘Control Panel’. Now choose the option ‘Phone and Modem’.
- Here you will see three tabs, the dialing rules, modems, and advanced. Choose the tab ‘Modems’. As you click on it, you will see modems installed on your PC. To repair the Modem Error 633, select and remove all the incompatible software and modems that are not present and click ‘OK’.
- Now to bring the changes into effect, restart your system with the modem plugged in and try connecting to the internet again.
Solution 2: Change the Communication Ports
If the error occurs because the modem is not properly configured, then this solution is possibly the best way to resolve this error. Here’s what you need to do:- Click on the Start menu and choose My Computer.
- Now click on the option ‘Manage’ to open the Computer Management Window.
- Once it opens, click the option ‘Device Manager and then expand the option modems. Click on Properties, then the Advanced tab, and the Advanced Port Settings button.
- As you click on the Advanced Port Settings, then click on the COM Port Number drop-down box.
- Choose a new Communication Port. However, make sure it is not already in use.
- Once you make changes, click ‘OK’ and then restart your PC.
- Now Open Device Manager again. Open the Modern Properties Window and then Click the Diagnostics tab.
- After that view the command response window to verify if the error is fixed. If yes, then create a new dial-up connection and connect to the internet with ease.
Solution 3: Disable the Startup items
- Another way to resolve Modem Error 633 on your PC is to go to the start menu and type ‘msconfig’ into the search box and then press ‘enter’.
- Open the misconfig.exe program. As you open it, you will see 4 tabs, General, Boot, Service, Start-up, and Tools.
- Now click on the ‘Start-up’, ‘Disable All’, and then press Apply.
- After you press Apply, a window will pop up asking to restart the computer.
- Confirm it and click restart.
- Once the computer restarts now try connecting to the internet again. This will hopefully resolve the Modem Error 633.


Once the device window opens, click once on printers and scanners, and on the right window go to the bottom and uncheck Let windows manage my default printer.
Unchecking that box will let Windows know that we do not wish anymore for him to set our default printers according to their use. Once the checkbox is clear go up to your printer list and click on the printer you wish to use as the default one. I will choose Microsoft Print to PDF as my default printer and click on it. Once the printer is clicked option menu will appear.
When the option menu appears under the printer name, click on Manage which will take you to the printer management screen. When you are on the manage screen, click on the Set as default button, and you are done.




Keeping your PC clean is not rocket science and you can do it with things you already and probably have in your house. One thing that I would recommend tho to purchase is antistatic gloves since they could prevent any kind of electrostatic discharges thus protecting your electric components.
If you have the option to disconnect your PC and get it outdoors, I would highly recommend this approach since all the dust will be dusted outside and not in the room where your computer is. If you can not it is still ok, but since some portion of dust will be set in the room, you might need to dust your room after cleaning your computer.
