Right sorry, I extracted the zip on a folder in my desktop, I then ran the launch.bat file and it is stuck on Creating Railcraft Save File.
If I close the cmd and try to run the java tekkit.jar, with the Web start launcher, this message comes up:
Error: could not load javaws10 (the first time I tried), javaws11(the second time I tried).
Exception:
CouldNotLoadArgumentException[ Could not load file/URL specified: C:\\Users\\NACHOH~1\\AppData\\Local\\Temp\\javaws13]
at com.sun.javaws.Main.launchApp(Unknown Source)
at com.sun.javaws.Main.continueInSecureThread(Unknown Source)
at com.sun.javaws.Main$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Wrapped exception:
java.io.IOException: File too large
at com.sun.javaws.jnl.LaunchDescFactory.buildDescriptor(Unknown Source)
at com.sun.javaws.Main.launchApp(Unknown Source)
at com.sun.javaws.Main.continueInSecureThread(Unknown Source)
at com.sun.javaws.Main$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)