Define the purpose of the computer
Choose a CPU
Choose a compatible motherboard
Choose RAM
Choose storage
Choose a power supply
Choose a case
Choose a graphics card if needed
Choose cooling components
Check component compatibility
Gather tools and materials
Install the CPU on the motherboard
Install the RAM on the motherboard
Install the storage drive
Install the CPU cooler
Mount the motherboard in the case
Install the power supply in the case
Install the graphics card if used
Connect power cables
Connect front panel cables
Connect case fans
Double-check all connections
Power on the computer
Enter BIOS or UEFI
Verify hardware is detected
Install the operating system
Install drivers
Update the system
Test the computer
Organize cables
Close the case
Set up software and preferences