MSINET.ocx is an activeX control (MS Internet Transfer Control) dated 09/03/2004
On my various sys, which are 64bit sys, its located in the C:\Widows\Syswow64 folder
If you are able to locate MSINET.ocx in a windows search (and only IF)
Try;
Start> cmd.exe rt click to run as admin then enter,
regsvr32 msinet.ocx
Does this err msg appear when you start the PC or only when you use your browser? and if thats the case its likely caused by a browser extension, so try disabling any third party extensions in your browser