My .jar files won't open

So recently I've wanted to install 1.8.9 minecraft forge onto my computer, to make my minecraft experience even better (i know i'm a nerd shut up) but when I download the .jar file, and run it, it comes up with this message:

"Unable to install Java
There are errors in the following switches: C:\Users\(name)\Downloads\forge-1.8.9-11…
Check that the commands are valid and try again.

I personally son t really know what the freak this thing is talking about, and I've looked everywhere online to see if i could resolve this problem, I tried, but it didn't work, so now i'm here, asking how to do it. Btw, I'm on windows 7.

Stop it 02.06.2017

A jar file is a java program.

To use a jar file you type something like: java my.jar

You can also use flags, which are additional options. For instance if you want java to limit itself to a fixed amount of RAM, you use an extra option on the command line.

You apparently used an option or flag that your version of Java doesn't recognize. Either you made a typo, or, you're using an older version of Java that might not support that option.

Of course this all assumes you've actually installed the correct version of Java on your computer. To just run a Java program you need the JRE (Java Runtime Environment) but if you're writing your own Java programs you need the JDK (Java Developer's Kit.) If you aren't sure which one you need, install the JDK as it includes the JRE.

PoohBearPenguin 02.06.2017