Screwed up system variables

[Paisa90]

Hello all. I was having the "cant find main class" error so I read around that it could be the system variables. I changed them several times and reinstalled Java SDK many times to try to solve this but nothing happened, so I went on and erased all the system variables related to Java because I thought they'd be restored when I reinstalled the SDK.

Well they didnt and now I cant even use a website with Java because I get some "Java not detected" message.

I dont remember which system variables I erased, can you give me a hand? Thank you a lot

 

[Paisa90]

EDIT:
I remember I deleted the CLASSPATH, JAVAHOME and JAVA system variables. I can create them again but I dont know what to put under "location". Help me out please