I use the zip file to add jdownloader to my Windows 7 programs. Kind of like a portable/no install. Anyway, I'm using 0.9.581 and I had to update Java today and when I did I restarted and once again I got the launch4 error or need to install java re 1.50 and I wasn't able to do that for some odd reason. I tried to change the shortcut to the jd.jar and I couldn't do that. Finally I messed around on the jdupdate and something must have happened positive because the jdjar I was able to use as a shortcut without installing any old java runtimes.:outch: I don't really know how I got that to work and that is why I'm here. Did I miss updating something or do people actually run old JRE's? (javaRE) I'd really like to know how or what to do when you have to update java and the shortcut that I'm using at the time doesn't want to cooperate? I was using the jdexe before I started all this and I just ried to use it again to see what it would do and it is still asking me to use that old jre. Strange! It has me going back and forth between jdjar and exe as far as shortcuts go, but if something happens now with the jdjar shortcut, I'm not going back to the old javaRE.

[Jiaz]

The old JDownloader.exe only works with 32bit Java. It can be that auto-update installed 64bit java which broke the startwrapper.
You can simply start JDownloader.jar, the exe just do "java -jar JDownloader.jar".
Switching from 32bit to 64bit java will break the Installer, so please stay with one version

Originally Posted by Jiaz

The old JDownloader.exe only works with 32bit Java. It can be that auto-update installed 64bit java which broke the startwrapper.
You can simply start JDownloader.jar, the exe just do "java -jar JDownloader.jar".
Switching from 32bit to 64bit java will break the Installer, so please stay with one version

Even though my jdownloader is working right now I feel according to your post that I may be looking at a problem. At this point I am running this as a portable with jdownloader.jar as a shortcut to start it at boot. Now when I had the problem yesterday and the exe would no longer work java would not let me update to that old version as it claimed it was a security vulnerability. I just went and looked at what's installed right now and I have 3 versions of java which seems a bit excessive. First I have java 6 update 33, java 7 update 5, java 7 update 5 (64 bit), java FX runtime 2.1.1, that was right next to the 3 normal java installs. This is where I'm at right now and I think I can see where jdownloader.exe broke. Too much different java versions? So, that said what should I do if anything at all. You know that I'm running jdownloader.jar as the shortcut and it is working. I do know though that I certainly don't need that much java. Even though I am running Windows 7 x64.:confused:All this just to keep up with jdownloader. I hope you can understand this, and thanks for the replies.

[Jiaz]

You should always be able to directly start (double click) the JDownloader.jar file. Java normally associates jar with java. The exe is just a wrapper doing a java -jar JDownloader.jar call
Problem with exe is that 32bit Exe only works with 32bit java.
JDownloader2 runs fine with java >=1.6, JDownloader1 also runs in 1.5