Morsemorta

No, can you help me or not?

accident

So to put it simply my friend has a relatively poor computer, but he has always been able to run Minecraft. The only trouble he has ever had is the OpenGL mode/bad drivers error, but he figured out how to solve that and hasn't run into trouble in a while. Recently I got into Tekkit, and so he wanted to try it out. At first it didn't work for him, but I came over and solved the problem. He just needed to use the .jar version. Now here is where I believed the problem started, before I tried the .jar I suspected that he had multiple versions of Java and that that was causing the problem. Naturally I went in and deleted all his Java stuff, which he did have multiple of, and then I re-installed the latest Java. After fixing the issue by using the .jar file Tekkit would open but goes to a white screen before even reaching the Mojang screen. After I saw that happen I launched vanilla again and it said OpenGL/bad driver again. My friend tried his usual fixes, but they didn't work. So my question to you is what is going on here, and how can I fix it? But also, might I have deleted something else Java related that I shouldn't have, and now I still need to re-install it?

So to put it simply my friend has a relatively poor computer, but he has always been able to run Minecraft. The only trouble he has ever had is the OpenGL mode/bad drivers error, but he figured out how to solve that and hasn't run into trouble in a while. Recently I got into Tekkit, and so he wanted to try it out. At first it didn't work for him, but I came over and solved the problem. He just needed to use the .jar version. Now here is where I believed the problem started, before I tried the .jar I suspected that he had multiple versions of Java and that that was causing the problem. Naturally I went in and deleted all his Java stuff, which he did have multiple of, and then I re-installed the latest Java. After fixing the issue by using the .jar file Tekkit would open but goes to a white screen before even reaching the Mojang screen. After I saw that happen I launched vanilla again and it said OpenGL/bad driver again. My friend tried his usual fixes, but they didn't work. So my question to you is what is going on here, and how can I fix it? But also, might I have deleted something else Java related that I shouldn't have, and now I still need to re-install it?