Every time I boot Ubuntu ask for installation

[nertion]

Yes

thank you !

[nertion]

If I take away then pen, then the pc runs windows.

[oldfred]

What brand/model system?
UEFI or BIOS install?
What video card/chip?

To see what is installed where:
May be best to see details, use ppa version with your live installer or any working install, not older Boot-Repair ISO:
Please copy & paste link to the Boot-info summary report ( do not post report), the auto fix sometimes can create more issues.
https://help.ubuntu.com/community/Boot-Repair

[nertion]

I use the BIOS por booting. The things is that if I go to the boot menu and go through the option: "Boot from first hard disk" I can get into my user and my docs. If I don't go trough this option and just do a normal booting, is when the installation process appears.

Thank you very much!

[yancek]

I don't think you will be able to get any help until you run boot repair, suggested and link posted in post 13 above. There are too many possibilities and everyone will just be guessing without details.

[nertion]

Yes... I tried the boot repair, and said something like this: " For using the boot repair star the pc with the UEFI and not with the legacy. If I do that, doesn't even run ubuntu...
thank you!

[oldfred]

You have newer UEFI hardware.
And then it depends on whether installs are UEFI or BIOS on which way you should boot Ubuntu live installer & add Boot-Repair.
Did you run the report? That should not matter unless your installs are UEFI and then a UEFI report includes a bit more info.

[nertion]

Should I past here the link to the boot repair info page?
thank you!

[oldfred]

Please post link and in clickable format so we can just click on the link to see details of your configuration.

[1clue]

To me it sounds like you put a livecd installer on the USB stick, and then clicked 'try Ubuntu' and are running from the USB stick.

Did you actually format your drive and install Ubuntu, or did you just click 'try Ubuntu?'