The methods to solve win1' s prompt that MFC 11 u.dll is lost are as follows:

1. First, open Baidu browser and search for the download page of MFC 11 u.dll.

2. then, in the download page, click the open download button to download.

3. Then copy and paste the downloaded file to? C: in the C：Windows\System32 folder.

4. then open the start menu bar and select the "run" option.

5. then enter "regsvr32 mfc1u.dll" in the running window and press enter to confirm.