Can't download .jar files

[Crimvael]

I know this is an unusual place to ask, but I've redownloaded Java and I still can't install any .jar files. When I try to, it just opens cmd and it closes after a split second. If I open with 7Zip, it says unsupported command.

Any advice? Even the tiniest bit will help me immensely. Thanks!

 

[Crimvael]

Are you sure you are running the right version of Java on your machine and not outdated, and did you restart your pc after uninstalling a jar file before adding it again.

I checked.

Try to right click > Open with > Java

Same thing occurs.

 

[iCodeHaven]

What's the jar exactly? It may not be a program!
Options:
Right click -> Run as administrator
or
Update to Java 8

Those are the only solutions I can think of right now..

 

[Crimvael]

Solved off-site. Thanks for everyone who replied!