My laptop was on XP. Well if you heard of google you can google on where to allow you to manually edit it on W7. You can also try this:
Do this...
put your minecraft.exe in any folder, just make sure you copy the path, and rename it to minecraft.jar
then open notepad, paste this line
java -Xmx800m -jar "PATH\Minecraft.jar
paste the path to the folder where minecraft is into PATH
then click save -> save it as NAME.bat (NAME can be anything that you want)
then from now on, double-click this NAME.bat file to open minecraft... and do not close the cmd that will open...
example:
I put minecraft.jar on C:\
so on notepad I do this:
java -Xmx800m -jar "C:\Minecraft.jar
You open jar files with Java.
Showing the same error. Also, if it makes any difference I'm trying to play regular minecraft offline. Here's what is says:
Bad video card drivers!
-----------------------
Minecraft was unable to start because it failed to find an accelerated OpenGL mode.
This can usually be fixed by updating the video card drivers.
--- BEGIN ERROR REPORT 7fe0271 --------
Generated 01/11/11 17:51
Minecraft: Minecraft Beta 1.7.3
OS: Windows 7 (x86) version 6.1
Java: 1.7.0, Oracle Corporation
VM: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
LWJGL: 2.4.2
[failed to get system properties (java.lang.NullPointerException)]
org.lwjgl.LWJGLException: Pixel format not accelerated
at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)
at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)
at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:185)
at org.lwjgl.opengl.Display.createWindow(Display.java:311)
at org.lwjgl.opengl.Display.create(Display.java:856)
at org.lwjgl.opengl.Display.create(Display.java:784)
at org.lwjgl.opengl.Display.create(Display.java:765)
at net.minecraft.client.Minecraft.a(SourceFile:294)
at net.minecraft.client.Minecraft.run(SourceFile:716)
at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT e3abbb9 ----------