That’s definitely unusual. Intel Virtualization Technology (VT-x) should not enable or disable itself randomly — it’s a BIOS/UEFI setting that typically stays how you left it unless:
🧠 Possible Causes:
- BIOS/UEFI Reset Itself
- If your CMOS battery is weak or dying, your BIOS settings (including VT-x) might reset to defaults, which can randomly disable virtualization.
- Power outages or improper shutdowns may also trigger BIOS resets on some systems.
- BIOS Update (Automatic or Manual)
- If your system or motherboard manufacturer pushed a BIOS/firmware update, it might have reset VT-x settings.
- Some Windows systems (especially laptops) may auto-update BIOS during Windows Update (e.g., Lenovo, HP, Dell).
- Overclocking or BIOS Tweaking Software
- Apps like Intel XTU, MSI Dragon Center, or ASUS AI Suite might change BIOS settings if configured to “optimize” or apply presets.
- If you installed or used any system optimization tool, it might be toggling VT-x behind the scenes.
- Malware or Rootkits
- Rare but possible: some advanced malware can manipulate virtualization settings to bypass detection or interfere with sandboxing tools.
- Dual Boot Systems
- Booting into certain operating systems or using some Linux distros (or hypervisors) may modify VT-x state if Secure Boot or virtualization dependencies are toggled.
🛠️ What You Can Do:
- Check BIOS Battery: If your PC is a bit old, try replacing the CMOS battery (usually a CR2032 coin cell).
- Manually Set VT-x Again: Reboot to BIOS and manually enable Intel VT-x, save settings, and exit.
- Check for BIOS Updates: See if your manufacturer has pushed any recent updates.
- Disable Fast Boot (temporarily): It can sometimes skip BIOS settings properly applying.
- Run Antivirus/Malware Scan: Just in case it’s something malicious.
- Monitor With Event Viewer: See if there are events around the same time VT-x gets disabled — it might show power loss or update events.