Hi @hcmgkss
2 possible reasons:
1. spacedesk MSI installer is in inaccessible location, please make sure that the spacedesk msi installer is in your local disk e.g. Download folder in C:\ directory.
2. spacedesk MSI installer is corrupted or probably you downloaded an incomplete file, please check the file size.
For spacedesk_driver_Win_10_64_v1067_BETA.msi, it should have 4.66MB file size.
If #2 is the case your side, please download again the spacedesk MSI installer at https://forum.spacedesk.net#download.
By the way, we moved your post to a separate topic to avoid confusion.