I have been trying to install the free ST8 2D program on a 64 bit laptop with windows10 but it seems to be a " .part" file and I cant find anything to open it with. Probably an obvious one but has anyone any ideas?
The .part file extension is typically a temporary file extension used by your web browser download manager to download files under. Once a file has been completely downloaded the web browser should then automatically rename the downloaded .part to it's real name.
The fact that you still have the .part file extension would appear to indicate that your download was interrupted and did not completely download properly, As such, you should download ST8 again.
You could also try renaming the .part extension to .exe but I'm betting that won't work.