A clean installation of Windows involves formatting the system drive and installing a fresh copy of the OS. This is done through either UEFI or Legacy BIOS boot modes.
- Remove old OS, files, viruses, or bloatware
- Start fresh with optimal performance
- Switch between BIOS and UEFI modes if needed
- ✅ Windows ISO File (from Microsoft)
- ✅ Rufus or similar tool (for bootable USB creation)
- ✅ 8GB+ USB Drive
- ✅ Backup important data (clean install will erase everything)
| Feature |
UEFI |
Legacy BIOS |
| Boot Mode |
Modern, faster, secure |
Traditional, slower |
| Partition |
GPT (GUID Partition Table) |
MBR (Master Boot Record) |
| Support |
64-bit only, large disks (>2TB) |
32/64-bit, limited to 2TB disks |
- Use Rufus:
- Partition scheme: GPT for UEFI, MBR for BIOS
- File system: FAT32 (for UEFI), NTFS (for BIOS)
- Press
Del, F2, or Esc during startup
- Enable UEFI or Legacy Boot, disable Secure Boot if needed
- Set USB as first boot device
- Save changes and restart
- System should load the Windows Setup screen
- Choose Custom: Install Windows only (advanced)
- Delete all partitions (optional for full clean install)
- Select unallocated space → Click Next
- Windows will install, restart multiple times
- Choose language, time zone, keyboard, and user info
- Skip/Sign in with Microsoft Account if required
- Install drivers (manually or via Windows Update)
- Activate Windows using license key
- Install essential software (browser, antivirus, Office, etc.)
- Enable BitLocker (UEFI + TPM) for disk encryption (optional)
A clean install of Windows via UEFI or BIOS ensures optimal performance and a fresh start. UEFI is preferred for modern systems with GPT and advanced features, while BIOS supports legacy systems.