Symptoms: VirtualBox shows a VT-x/AMD-V error, KM OS does not start, or the 64-bit guest option is missing.

1. Shut down Windows completely and restart the laptop.
2. Enter BIOS/UEFI setup using the key shown by your laptop manufacturer.
3. Enable Intel VT-x, Intel Virtualization Technology, AMD-V or SVM Mode.
4. Save BIOS/UEFI changes and boot into Windows again.
5. Open VirtualBox and start KM OS.

If the 64-bit option is still missing, Windows hypervisor features may be interfering. Check this with the Kernel Masters support team before making major Windows changes.

Symptoms: import stops midway, the image is not accepted, or VirtualBox reports an appliance import error.

1. Confirm that the file is fully downloaded and has the expected .ova extension.
2. Do not import directly from a partially downloaded file or unstable external drive.
3. Keep sufficient free disk space before importing. VM import needs extra working space during extraction.
4. Move the OVA file to a simple local path such as D:\KMOS or C:\KMOS.
5. Restart VirtualBox and try File → Import Appliance again.

If the same error repeats, download the OVA again from the official Kernel Masters source.

Symptoms: slow boot, lagging mouse, terminal delay, browser freezing or long build time.

1. Close heavy Windows applications before starting the VM.
2. Use SSD storage wherever possible. Running a VM from HDD can be very slow.
3. Do not allocate all host RAM to the VM. Windows also needs memory to run smoothly.
4. Allocate CPU cores carefully. A 4-core laptop should not give all cores to the VM.
5. Avoid running multiple VMs at the same time on low-RAM systems.
6. Create a snapshot only after the VM becomes stable and verified.

If performance is still poor, use the lighter KM OS version recommended for low-spec systems.

Symptoms: browser does not open websites, apt update fails, Git clone fails or the network icon shows disconnected.

1. Confirm that internet works on Windows first.
2. Shut down KM OS, open VM settings and check whether Network Adapter is enabled.
3. Use the network mode recommended by Kernel Masters for your course setup.
4. Start KM OS again and test the browser.
5. Open terminal and test basic connectivity:

ping -c 4 8.8.8.8
ping -c 4 google.com

If the first command works but the second fails, it may be a DNS issue. Share the output with support.

Symptoms: Windows shared folder is missing, files are not accessible, or permission is denied.

1. In VirtualBox, open VM settings and confirm that the shared folder is added.
2. Enable auto-mount if that is part of the Kernel Masters setup.
3. Start KM OS and check the shared-folder location provided by the trainer.
4. Confirm that Guest Additions are active.
5. If permission is denied, the Linux user may need access to the shared-folder group:

groups $USER
sudo usermod -aG vboxsf $USER
sudo reboot

After reboot, check the shared folder again. Do not change random permissions on system folders.

Symptoms: development board, USB-to-serial adapter or storage device is visible in Windows but not inside KM OS.

1. Install the VirtualBox Extension Pack matching the VirtualBox version.
2. Shut down KM OS and open VM USB settings.
3. Enable the USB controller recommended by Kernel Masters.
4. Start KM OS and connect the USB device.
5. From the VirtualBox menu, select Devices → USB and attach the required device to the VM.
6. Inside KM OS, check whether the device is detected:

lsusb
dmesg | tail -30

If Windows captures the device again, disconnect and reconnect it, then attach it from the VirtualBox USB menu.

Symptoms: full-screen mode does not resize properly, shared clipboard stops, drag-and-drop fails or the display remains fixed after a Linux kernel update.

This usually means VirtualBox Guest Additions kernel modules need to be rebuilt for the currently running Linux kernel.

sudo apt update
sudo apt install --reinstall build-essential dkms linux-headers-$(uname -r)
sudo rcvboxadd setup
sudo reboot

If the issue continues, manually reinstall Guest Additions using the ISO method below.

From the running VirtualBox window, select:

Devices → Insert Guest Additions CD Image

Then run inside KM OS:

cd /media/$USER/VBox_GAs_*
sudo sh ./VBoxLinuxAdditions.run
sudo reboot

If the ISO does not mount automatically, use this manual mount method:

sudo mkdir -p /mnt/vbox-guest-additions
sudo mount /dev/cdrom /mnt/vbox-guest-additions
cd /mnt/vbox-guest-additions
sudo sh ./VBoxLinuxAdditions.run
sudo reboot

If installation fails, share the error from this log with support:

/var/log/vboxadd-setup.log

No. KM OS is prepared as a standardized Linux-based learning environment for Kernel Masters students wherever the course requires Linux tools, programming, embedded development or system-level workflows.

No. KM OS is an Ubuntu-based environment customized with tools, packages and configurations required for Kernel Masters practical learning.

Yes. KM OS behaves like Ubuntu. However, major upgrades or package changes should be done carefully because they may affect course compatibility.

Apply only recommended updates. Avoid uncontrolled upgrades before practical sessions. Always create a snapshot before major system or package changes.

Use the official Kernel Masters student-support channel and share the exact error message, screenshot, VirtualBox version, Extension Pack version and KM OS version.