I downgraded from windows 8 to windows 7 (this is not a new computer) just because i didn't like the layout of windows 8, i downloaded all of my drivers and minecraft started and worked but after a couple days i got back on and my minecraft character would skip every few seconds. i put vsync on so i could keep it at 60 fps and it helped a bit. I already tried reinstalling java and it didnt work.
here is a video for an example of it
Welcome to the Forum.
If you're overclocking:
If you're using OverDrive, set everything back to normal and overclock in the BIOS instead
If you're using the BIOS, set everything back to the default settings.
EDIT: it was the processor that was overclocked and caused this thanks for your help
here is a video for an example of it