Ubuntu 20.04安装失败及启动异常后的重新安装方法咨询

Hey there, sorry to hear you hit snags trying to get Ubuntu 20.04 up and running—let’s break down how to start fresh and get it installed smoothly this time.

Step 1: Refresh your installation media first #

• Re-download the Ubuntu 20.04 ISO: Corrupted downloads are a common culprit behind boot issues. Grab the official Ubuntu 20.04 ISO file (64-bit is the standard for modern systems).
• Verify the ISO’s integrity: Match the file’s hash value against the official one provided alongside the download. On Windows, use certutil -hashfile <path-to-iso> SHA256; on macOS/Linux, use sha256sum <path-to-iso>. If they don’t match, re-download the file.
• Recreate the bootable USB: Use reliable tools like Rufus (for Windows) or the built-in Startup Disk Creator (if you can access another Ubuntu system). For Linux/macOS users, the dd command works too: sudo dd if=/path/to/ubuntu.iso of=/dev/sdX bs=4M status=progress (replace /dev/sdX with your USB drive—double-check this to avoid overwriting your main disk!).

Step 2: Prep your system before booting the installer #

• Backup all critical data: If you’re reinstalling on a disk with existing files, copy everything important to an external drive— the "erase disk" install option will wipe all data.
• Check BIOS/UEFI settings: Restart your computer and press the key to enter BIOS/UEFI (usually F2, F10, Del, or Esc—look for on-screen prompts):
  • Set your boot order to prioritize the USB drive first.
  • If you saw odd boot errors, try temporarily disabling Secure Boot (some older hardware or third-party components conflict with it; you can re-enable it later if the install works).
  • Disable Fast Startup if dual-booting with Windows—this can cause disk access conflicts.

Step 3: Run the installer carefully #

• Boot from the USB drive: Restart your computer, and it should load the Ubuntu installer menu. If not, double-check your BIOS boot order.
• Choose Install Ubuntu (skip "Try Ubuntu" unless you want to test hardware compatibility first).
• Follow prompts for language, keyboard layout, and network setup. If you have stable internet, check "Download updates while installing Ubuntu" to grab fixes and drivers during setup.
• When reaching the disk setup screen:
  • For a clean, hassle-free install (with data backed up), select Erase disk and install Ubuntu.
  • If you’re dual-booting or need custom partitions, pick "Something else"—only do this if you’re comfortable managing disk partitions.
• Complete the rest of the setup (user account, time zone) and let the installer finish. When prompted, restart and remove the USB drive.

Step 4: Troubleshoot if issues persist #

If you still get strange errors after reinstalling:

• Boot into "Try Ubuntu without installing" from the USB. If the system runs smoothly here, the issue might be with installation settings or post-install drivers.
• For graphics-related errors (common with NVIDIA GPUs), once in the system, open Software & Updates, go to the Additional Drivers tab, and install the recommended proprietary driver for your card.
• Confirm your hardware meets Ubuntu 20.04’s requirements: at least 2GB RAM, 25GB disk space, and a 64-bit processor.

备注：内容来源于stack exchange，提问作者Seán Hennessey