1. Background
Users who use the Windows 11 virtual machine in Parallels Desktop often encounter that the upload speed of Windows becomes 10KB/s, especially when sending QQ attachments or Foxmail. Generally, restarting cannot solve this problem.
At present, this problem may be related to hibernation. If the Mac lid is closed many times, it is more likely to occur. This problem exists in PD17-PD18.2 versions.
2. Solution 1: Reset the network
Start→Run under Windows, enter cmd, choose to run as administrator, and enter the following command:
netsh winsock reset
Restart the computer after execution, and the network speed can be restored.
3. Solution 2: Adjust the virtual network card option settings
1. Desktop computer → properties, select the device manager on the left
2. Find the network card of the virtual machine, usually Parallels VirtIO Ethernet Adapter
3. Right-click the network card and select Properties. Select the Offload.Tx.LSO property in the Advanced tab, and adjust the value to Disabled.
Restore internet speed without restarting.
Note that after each upgrade of Parallels Desktop, this property may be reset and needs to be reset.