A few days ago,

I download Windown 7/8 Minecraft Launcher,

I reinstalled Minecraft after not opening,

Repairing and reinstalling do not seem to work...

from https://www.minecraft.net/en-us/download

And I'm using Win7.

Error:

Couldn't load launcher core from 'C:\Program Files (x86)\Minecraft Launcher\game\launcher.dll': LoacErrorNotPresent

If this is your first time runing Minecraft, plesase ensure you are connected to the internet so we can downliad updates.