The post discusses common reasons why TeamViewer shows a connection could not be established and describes simple methods to resolve connection failed or partner not connected problems.
Many users see the message “A connection could not be established” when they try to access a remote PC through TeamViewer. This often appears at important moments, which makes the situation more stressful. The error usually shows that TeamViewer cannot create a stable connection between the local device and the remote computer. As a result, the link fails before the session begins.
The table below gives a simple overview of the most common causes and explains what may be happening in the background.
| Cause | What it means |
|---|---|
| Weak or unstable network | TeamViewer cannot keep a steady link between both devices. |
| Incorrect TeamViewer ID or password | The system cannot match your login details with the remote PC. |
| Outdated TeamViewer version | Different versions make it difficult for both sides to connect normally. |
| Firewall or antivirus blocking | Security tools may prevent TeamViewer from reaching the remote device. |
| Remote PC is offline or asleep | The target computer is not available for connection. |
A clear view of these causes gives a better idea of where the problem comes from. Since the error often results from simple network limits or software conflicts, the issue usually has a straightforward explanation. This also brings more confidence, as the failure rarely points to a serious system problem but mainly reflects the connection conditions around both devices.
Step 1. Press Win + R, type in “services.msc”, then click OK.
Step 2. Find TeamViewer. Right-click it and then choose Restart.
Step 3. Wait for the process to finish. Then try to connect via TeamViewer again.
Step 1. Follow the steps above to stop TeamViewer from the Services first.
Step 2. Open Registry Editor by entering “regedit.exe” in the Run box. Navigate to: HKEY_CURRENT_USER > Software > TeamViewer. Delete the TeamViewer registry key.
Step 3. Open the PowerShell console with administrator privileges and run the following command to determine the creation date of the "C:Program Files" folder:
Get-Item "C:\Program Files" | select Name,CreationTime
Step 4.Use the NirCMD tool to change the creation date of the Program Files folder. Download it and run it from the elevated Command Prompt console as follows:
nircmdc.exe setfilefoldertime "C:\Program Files" now now
Step 5. Check if the CreationTime value of the directory has changed.
Step 6. Then, using one of the special tools available, change the MAC address of your network card. Alternatively, you can edit your MAC address through the registry by following the steps outlined below.
Step 7. To get the current MAC address of your network card, open command prompt, and run the following command:
Ipconfig /all
Pay attention to two parameters: Description (LAN card description) and Physical Address (MAC address).
Step 8. Then, open the Registry Editor again and go to the key: HKLM > SYSTEM > CurrentControlSet > Control > Class > {4d36e972-e325-11ce-bfc1-08002be10318}.
Step 9. Find DriverDesc option, where the description (name) of your NIC must be specified (for example, Intel(R) 82574L Gigabit Network Connection). When you've found the correct network card, double-click the NetworkAddress parameter. It specifies the network card's MAC (hardware) address. It is sufficient to change a single digit in the current MAC address, such as 000C299D4D80.
Step 10. As a result, the network card's MAC address is changed. You must now modify the VolumeID of the system partition. VolumeID (or Volume Serial Number) is a hard drive volume's unique identifier that is set during formatting. Use the console utility VolumeID v2.1 to change the VolumeID v2.1. VolumeId.zip should be downloaded and extracted.
Step 11. Open Command Prompt with Administrator privileges and run the following command to determine the current VolumeID:
vol
Volume Serial Number is 5E37-ECE1.
Step 12. Replace the current value with the new value 5E37-EC11:
c:\users\root\Downloads\VolumeID
Volumeid.exe c: 5E37-EC11
Step 13. Close the command prompt and restart your computer. Then restart TeamViewer, and you'll be given a new TeamViewer ID.
A corrupt TeamViewer entry in its host file could also lead to “TeamViewer can't connect”. In this case, you need to delete the TeamViewer section from the host file.
Step 1. Press Win + E to launch Windows Explorer.
Step 2. Go to View tab and tick Hidden items.
Step 3. Go to the following file path and open the hosts file with Notepad.
Step 4. Press Ctrl + F and type teamviewer, then click Find Next.
Step 5. If you don’t get any results, it means you don’t have any corrupt TeamViewer files on your PC. If you find words like #Teamviewer, right-click it and delete them.
Step 6. Press Ctrl + S to save the file, exit Notepad, and check whether the connection issue is solved.
If the “connection could not be established” error in TeamViewer continues to appear and the issue is still not solved, a reliable alternative such as AnyViewer becomes a practical choice. It helps avoid repeated connection failures and offers a stable remote access experience.
AnyViewer is known for its reliability and smooth performance. It provides fast and steady connections with no unexpected interruptions. Its free version has no time limits, which makes it suitable for long term use. It also supports several ways to access devices and transfer files, giving users more flexibility. Features such as screen sharing, control of multiple monitors, and access to several computers at the same time make remote work easier. Helpful tools during a session, including chat and image quality adjustment, improve user experience. It also works across platforms and allows users to control a Windows computer from Android or iOS devices.
For users who want a strong replacement for TeamViewer, AnyViewer offers complete and professional functions. It supports both attended and unattended access, which fits different working situations. It runs on Windows, macOS, Android and iOS, making cross device connections simple. Its strong ECC encryption keeps every session private and secure. Users with multiple screens can switch between monitors with ease. File transfer remains quick and smooth. It also allows unlimited concurrent sessions, which improves efficiency for IT teams and businesses.
Step 1. Install and run AnyViewer on both your work and home computers. Navigate to Log in and then Sign up for creating an AnyViewer account on the Controller computer (if you have already registered on the official website, you can log in directly).
Step 2. You should now see that you have successfully logged into AnyViewer. Your device will be assigned to the account automatically and listed on My devices list once logged in.
Step 3. Log in to the same AnyViewer account on both devices, then on your local device, go to Device, click the remote computer, and click One-click control to establish a direct connection.
Step 4. After successfully connecting, you will see the remote desktop. Then you can control it completely and provide remote support as if you were sitting in front of it.
The “connection could not be established” error in TeamViewer usually comes from network limits, software conflicts, or settings on either device. Understanding the common causes and trying the available solutions helps restore normal access in most situations. When the error continues to appear and the connection remains unstable, choosing a dependable remote access tool such as AnyViewer provides a smoother and more reliable experience. This ensures that remote work and support can continue without unnecessary interruptions.