Windows 7: HELP! mklink /J i wanna undo

Hello everyone basicly i wanted to make my minecraft faster, i found this tutorial ( How to Insanely Speed Up Minecraft! [REMADE] - YouTube )
on youtube.

So i followed on, but i didnt get a big result out of it.
the problem is now that ive made this function in cmd:
mklink /j %appdata%\.minecraft K:\



And i now cannot play minecraft because it cannot create the .minecraft folder on the C: driver for some reason
Please help me, tell me if you need more information please.
THANKS!

This seems strange, given that minecraft does create a fodler c:\users\<yourname>\appdata\roaming\.minecraft. If you indeed created the junction exactly as the command above it should have complained, since mklink /j can't create a junction when a folder or file with the same name already exists.

Either way, the only way you can undo this is to delete the junction. You can do that by navigating to c:\users\<yourname>\appdata\roaming, and delete the .minecraft entry.

replace <yourname> with the name you are logged into your computer as. For example, my account is called Tanya, so my %appdata% is c:\users\tanya\appdata\roaming.

Then uninstall\reinstall the game.

Edit: I just watched the yourtube video; IMHO there is no need to go installing Ramdisks these days. Minecraft is much faster than it used to be, and these programs just create more confusion for people. If you really want to get more speed out of minecraft, or any game for that matter, it might be more benefit to look at upgrading various components of your computer, like adding a solid state drive, a better video card or faster memory. I'm taking a stab in the dark here, because you haven't provided any system specs.

good luck.