[Pre-Install] Kubuntu 26.04 LTS Fails To Install On 4 Year Old Custom Desktop?

[savantsavior]

Hi,

I tried to install Kubuntu 26.04 LTS onto a 4 year old custom build desktop.
The installation fails at the very end.
Any ideas on how to fix the above?

Also, I did not see an option when installing to encrypt the OS storage device?
Was the above taken away or moved somewhere else?

SS

Desktop Specifications below:

jlp@Desktop-Megatron:~$ inxi -Farz
System:
Kernel: 7.0.0-22-generic arch: x86_64 bits: 64 compiler: gcc v: 15.2.0
clocksource: tsc avail: hpet,acpi_pm
parameters: BOOT_IMAGE=/boot/vmlinuz-7.0.0-22-generic
root=UUID=5fee0814-17c9-44d4-bdeb-7c9218efea69 ro quiet splash
Desktop: KDE Plasma v: 6.6.4 tk: Qt v: N/A info: frameworks v: 6.24.0
wm: kwin_x11 vt: 2 dm: SDDM Distro: Kubuntu 26.04 LTS (Resolute Raccoon)
base: Ubuntu
Machine:
Type: Desktop Mobo: ASUSTeK model: TUF GAMING X570-PLUS (WI-FI) v: Rev X.0x
serial: <superuser required> part-nu: SKU uuid: <superuser required>
Firmware: UEFI vendor: American Megatrends v: 5044 date: 01/04/2026
CPU:
Info: model: AMD Ryzen 7 5800X bits: 64 type: MT MCP arch: Zen 3+ gen: 3
level: v3 note: check built: 2022 process: TSMC n6 (7nm) family: 0x19 (25)
model-id: 0x21 (33) stepping: 2 microcode: 0xA201213
Topology: cpus: 1x dies: 1 clusters: 1 cores: 8 threads: 16 tpc: 2
smt: enabled cache: L1: 512 KiB desc: d-8x32 KiB; i-8x32 KiB L2: 4 MiB
desc: 8x512 KiB L3: 32 MiB desc: 1x32 MiB
Speed (MHz): avg: 3684 min/max: 556/4854 boost: enabled scaling:
driver: amd-pstate-epp governor: powersave cores: 1: 3684 2: 3684 3: 3684
4: 3684 5: 3684 6: 3684 7: 3684 8: 3684 9: 3684 10: 3684 11: 3684 12: 3684
13: 3684 14: 3684 15: 3684 16: 3684 bogomips: 121373
Flags-basic: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a
ssse3 svm
Vulnerabilities:
Type: gather_data_sampling status: Not affected
Type: ghostwrite status: Not affected
Type: indirect_target_selection status: Not affected
Type: itlb_multihit status: Not affected
Type: l1tf status: Not affected
Type: mds status: Not affected
Type: meltdown status: Not affected
Type: mmio_stale_data status: Not affected
Type: old_microcode status: Not affected
Type: reg_file_data_sampling status: Not affected
Type: retbleed status: Not affected
Type: spec_rstack_overflow mitigation: Safe RET
Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via
prctl
Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer
sanitization
Type: spectre_v2 mitigation: Retpolines; IBPB: conditional; IBRS_FW;
STIBP: always-on; RSB filling; PBRSB-eIBRS: Not affected; BHI: Not
affected
Type: srbds status: Not affected
Type: tsa mitigation: Clear CPU buffers
Type: tsx_async_abort status: Not affected
Type: vmscape mitigation: IBPB before exit to userspace
Graphics:
Device-1: NVIDIA GA106 [GeForce RTX 3060 Lite Hash Rate]
vendor: Micro-Star MSI driver: nvidia v: 595.71.05
alternate: nvidiafb,nouveau,nova_core,nvidia_drm non-free: 550-580.xx+
status: current (as of 2025-11; EOL~2026-12-xx) arch: Ampere code: GAxxx
process: TSMC n7 (7nm) built: 2020-2023 pcie: gen: 4 speed: 16 GT/s
lanes: 16 ports: active: none off: HDMI-A-1 empty: DP-1,DP-2,DP-3
bus-ID: 0b:00.0 chip-ID: 10de:2504 class-ID: 0300
Display: x11 server: X.Org v: 21.1.22 with: Xwayland v: 24.1.10
compositor: kwin_x11 driver: X: loaded: nvidia
unloaded: fbdev,modesetting,nouveau,vesa
gpu: nv_platform,nvidia,nvidia-nvswitch display-ID: :0 screens: 1
Screen-1: 0 s-res: 1920x1080 s-dpi: 101 s-size: 483x272mm (19.02x10.71")
s-diag: 554mm (21.82")
Monitor-1: HDMI-A-1 mapped: HDMI-0 note: disabled model: AOC 2252W
serial: <filter> built: 2015 res: mode: 1920x1080 hz: 60 scale: 100% (1)
dpi: 102 gamma: 1.2 size: 477x268mm (18.78x10.55") diag: 547mm (21.5")
ratio: 16:9 modes: max: 1920x1080 min: 640x480
API: EGL v: 1.5 hw: drv: nvidia platforms: device: 0 drv: nvidia device: 2
drv: swrast gbm: drv: nvidia surfaceless: drv: nvidia x11: drv: nvidia
inactive: wayland,device-1
API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: nvidia mesa v: 595.71.05
glx-v: 1.4 direct-render: yes renderer: NVIDIA GeForce RTX 3060/PCIe/SSE2
memory: 11.72 GiB
API: Vulkan v: 1.4.341 layers: 7 device: 0 type: discrete-gpu
name: NVIDIA GeForce RTX 3060 driver: nvidia v: 595.71.05
device-ID: 10de:2504 surfaces: N/A device: 1 type: cpu name: llvmpipe
(LLVM 21.1.8 256 bits) driver: mesa llvmpipe v: 26.0.3-1ubuntu1 (LLVM
21.1.8) device-ID: 10005:0000 surfaces: N/A
Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
de: kscreen-console,kscreen-doctor gpu: nvidia-settings,nvidia-smi
wl: wayland-info x11: xdriinfo, xdpyinfo, xprop, xrandr
Audio:
Device-1: NVIDIA GA106 High Definition Audio vendor: Micro-Star MSI
driver: snd_hda_intel v: kernel pcie: gen: 4 speed: 16 GT/s lanes: 16
bus-ID: 0b:00.1 chip-ID: 10de:228e class-ID: 0403
Device-2: Advanced Micro Devices [AMD] Starship/Matisse HD Audio
vendor: ASUSTeK driver: snd_hda_intel v: kernel pcie: gen: 4 speed: 16 GT/s
lanes: 16 bus-ID: 0d:00.4 chip-ID: 1022:1487 class-ID: 0403
API: ALSA v: k7.0.0-22-generic status: kernel-api
tools: alsactl,alsamixer,amixer
Server-1: PipeWire v: 1.6.2 status: active with: 1: pipewire-pulse
status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin
tools: pactl,pw-cat,pw-cli,wpctl
Network:
Device-1: Realtek RTL8125 2.5GbE driver: r8169 v: kernel pcie: gen: 2
speed: 5 GT/s lanes: 1 port: e000 bus-ID: 05:00.0 chip-ID: 10ec:8125
class-ID: 0200
IF: enp5s0 state: up speed: 1000 Mbps duplex: full mac: <filter>
Device-2: Intel Wi-Fi 5 Wireless-AC 9x6x [Thunder Peak] driver: iwlwifi
v: kernel pcie: gen: 2 speed: 5 GT/s lanes: 1 bus-ID: 06:00.0
chip-ID: 8086:2526 class-ID: 0280
IF: wlp6s0 state: down mac: <filter>
Device-3: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
vendor: ASUSTeK driver: r8169 v: kernel pcie: gen: 1 speed: 2.5 GT/s
lanes: 1 port: d000 bus-ID: 07:00.0 chip-ID: 10ec:8168 class-ID: 0200
IF: enp7s0 state: down mac: <filter>
Info: services: NetworkManager,wpa_supplicant
Bluetooth:
Device-1: Intel Wireless-AC 9260 Bluetooth Adapter driver: btusb v: 0.8
type: USB rev: 2.0 speed: 12 Mb/s lanes: 1 mode: 1.1 bus-ID: 3-5:4
chip-ID: 8087:0025 class-ID: e001
Report: hciconfig ID: hci0 rfk-id: 0 state: up address: <filter> bt-v: 5.1
lmp-v: 10 sub-v: 100 hci-v: 10 rev: 100 class-ID: 6c0104
Info: acl-mtu: 1021:4 sco-mtu: 96:6 link-policy: rswitch sniff
link-mode: peripheral accept service-classes: rendering, capturing, audio,
telephony
Drives:
Local Storage: total: 7.32 TiB used: 24.66 GiB (0.3%)
SMART Message: Unable to run smartctl. Root privileges required.
ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Intel model: SSDPEKNU020TZ
size: 1.86 TiB block-size: physical: 512 B logical: 512 B speed: 31.6 Gb/s
lanes: 4 tech: SSD serial: <filter> fw-rev: 002C temp: 31.9 C scheme: GPT
ID-2: /dev/nvme1n1 maj-min: 259:3 vendor: Samsung model: SSD 980 PRO 2TB
size: 1.82 TiB block-size: physical: 512 B logical: 512 B speed: 63.2 Gb/s
lanes: 4 tech: SSD serial: <filter> fw-rev: 5B2QGXA7 temp: 35.9 C
scheme: GPT
ID-3: /dev/sda maj-min: 8:0 vendor: Western Digital
model: WD40EFAX-68JH4N1 size: 3.64 TiB block-size: physical: 4096 B
logical: 512 B speed: 6.0 Gb/s tech: HDD rpm: 5400 serial: <filter>
fw-rev: 0A83 scheme: GPT
Partition:
ID-1: / raw-size: 1.86 TiB size: 1.83 TiB (98.37%) used: 24.65 GiB (1.3%)
fs: ext4 dev: /dev/nvme0n1p2 maj-min: 259:2
ID-2: /boot/efi raw-size: 300 MiB size: 299.4 MiB (99.80%)
used: 8.1 MiB (2.7%) fs: vfat dev: /dev/nvme0n1p1 maj-min: 259:1
Swap:
Kernel: swappiness: 60 (default) cache-pressure: 100 (default) zswap: no
ID-1: swap-1 type: file size: 512 MiB used: 0 KiB (0.0%) priority: -1
file: /swapfile
Sensors:
System Temperatures: cpu: 50.6 C mobo: N/A gpu: nvidia temp: 40 C
Fan Speeds (rpm): N/A gpu: nvidia fan: 0%
Repos:
Packages: 2402 pm: dpkg pkgs: 2391 libs: 1368
tools: apt,apt-get,aptitude,synaptic pm: snap pkgs: 11
Active apt repos in: /etc/apt/sources.list.d/insync.list
1: deb [signed-by=/etc/apt/trusted.gpg.d/insynchq.gpg] http://apt.insync.io/ubuntu resolute non-free contrib
Active apt repos in: /etc/apt/sources.list.d/ubuntu.sources
1: deb http://us.archive.ubuntu.com/ubuntu resolute resolute-updates resolute-backports main universe restricted multiverse
2: deb http://security.ubuntu.com/ubuntu/ resolute-security main universe restricted multiverse
Info:
Memory: total: 64 GiB note: est. available: 62.7 GiB used: 3.08 GiB (4.9%)
Processes: 388 Power: uptime: 5m states: freeze,mem,disk suspend: deep
avail: s2idle wakeups: 0 hibernate: platform avail: shutdown, reboot,
suspend, test_resume image: 23.04 GiB services: org_kde_powerdevil,
power-profiles-daemon, upowerd Init: systemd v: 259 default: graphical
tool: systemctl
Compilers: N/A Shell: Bash v: 5.3.9 running-in: konsole inxi: 3.3.40
jlp@Desktop-Megatron:~$

[claydoh]

Also, I did not see an option when installing to encrypt the OS storage device?

https://www.kubuntuforums.net/forum/...904#post691904

The installation fails at the very end.

Any error message?
If you click the icon to the very right of the progress bar, at the bottom of the installer window, it will show the logs.
The exact failure may be a fairly simple cleanup, or it may have failed on the grub install.

But the installer failing at the end is not likely a hardware issue.

Other than verifying your ISO image and your USB stick, you might also try a different stick, using different tools to create the USB ( I like Ventoy).

A trick that *may* work if this persists, and it is failing on the grub install is to disconnect the network. This prevents it from downloading a grub update, and using what is on the ISO. I havn't seen this on 26.04, but I have seen it on other releases, as well as other distros that use Calamares as the installer.

[savantsavior]

Hi,

Downloaded the ISO via Torrent and checked the ISO 3 times.
Used a brand new 64GB USB3 flash drive.
Still same "Installation Failed" at the end?

I already tried everything you listed above, still fails?
After the install fails, I tried to click the icon to get the logs, but that crashes the installer?

About to give up, this 26.04 LTS release does not like my hardware...

Strangely enough, it seems not to be fatal, if I reboot to the new Kubuntu 26.04 LTS it boots and updates fine??
Very strange.

My main distro is CachyOS, just wanted to have an *Ubuntu on my secondary storage device.

SS