i have tried install HA OS on my old laptop following this guide.
So i installed it on my USB but then windows pops up and and tells me that there now is 7 partitions on my usb drive that i need to format has annybody tried this and have anny idea on how to fix it?
I have tried flashing it again with etcher and also with Rufus.
You don’t “fix it” there is nothing wrong with it. You have created a Home Assistant Operating System on your USB drive, this is not a bootable installer but the actual OS.
What you want to do is to create this on a system drive your old laptop uses. The instructions are quite clear about how to do this.