Hey guys, first of all if this is the wrong category than I'm sorry but I really didn't know where to post this thread.
Anyway I recently installed ubuntu on an external hard drive and it was booting up fine for a while, but later on the pc starting taking too much time, 2-3 minutes on the intel motherboard screen, and I thought that maybe it's because the PC is booting from the external hard drive. But as I soon found out, after removing the hard drive and trying again, that it wasn't that. So, any of you guys know what the problem is and/or how to solve it?

Thanks in advance.

Try clearing cmos by removing the CR2032 batery for a few minutes. You will need to set your bios up correctly afterwards.

Check your BIOS options, there is an option for not checking RAM and fast boot. I think it is some hardware your bios try to detect. try to remove all hardware connected to your MB one by one and check booting.

remove your fan and processor or you can use vaccume cleaner to clean the processor and power supply, clean with soft brush then check it again.