Help, Rundll32.exe & Win95

OS Windows 95.
Cannot open exe files, getting error message “Cannot find file’C:/WINDOWS/rundll32.exe’

There is a copy of rundll32.exe is my C drive, but will not let me copy any files, so I can paste it into my WINDOWS folder. I can copy and paste it in Safe mode, but when i reboot to normal mode, it is deleted out of WINDOWS folder again.

The AV program on the PC is out of date, and I cannot connect to the Internet to resubscribe to AV service. Because once I connect I cannot get any data transfer. But it says I am connected.

Please help.