Factors to consider before purchasing a computer:

1. Budget: Determine how much you are willing to spend on a computer before starting your search. This will help narrow down your options and prevent you from overspending.

2. Purpose: Consider what you will primarily be using the computer for (e.g. gaming, work, school, multimedia, etc.) as this will influence the specifications you need.

3. Operating system: Decide whether you prefer Windows, macOS, or Linux as your operating system. Each has its own set of features and compatibility with software.

4. Processor: The processor is the brain of the computer and determines its speed and performance. Consider getting a processor with multiple cores for multitasking.

5. RAM: Random Access Memory (RAM) affects the computer's ability to run multiple programs at once. Aim for at least 8GB of RAM for smooth performance.

6. Storage: Decide whether you want a traditional hard drive or a faster solid-state drive (SSD). SSDs are more expensive but offer faster boot times and improved performance.

7. Graphics card: If you plan on gaming or doing graphic-intensive tasks, consider getting a dedicated graphics card for better performance.

8. Display: Consider the size and resolution of the display, as well as whether you prefer a touchscreen or non-touchscreen display.

9. Connectivity: Check the number and types of ports available on the computer, such as USB, HDMI, and headphone jacks, to ensure they meet your needs.

10. Brand and warranty: Research different brands and read reviews to find a reliable computer manufacturer. Also, check the warranty and customer support options available for the computer.

1. Purpose and Usage:
- What are the primary tasks you will be using the computer for (e.g., gaming, video editing, work, browsing)?
- Determine the specific software and applications you need.

2. Operating System:
- Windows, macOS, or Linux?
- Consider compatibility with your desired software and hardware.

3. Budget:
- Set a realistic budget that aligns with your performance needs.
- Factor in additional costs for peripherals, software, and potential upgrades.

4. Processor (CPU):
- Number of cores and clock speed affect performance.
- Consider Intel or AMD, and their respective generations.

5. Memory (RAM):
- Amount needed depends on the tasks and software you use.
- DDR4 or DDR5 type affects speed and compatibility.

6. Storage:
- Capacity (HDD or SSD), speed, and durability.
- SSDs (Solid State Drives) offer significantly faster performance than HDDs (Hard Disk Drives).

7. Graphics Card (GPU):
- Essential for gaming, video editing, and demanding graphics applications.
- Consider the VRAM (video memory) and compatibility with your games.

8. Motherboard:
- Type (e.g., ATX, Mini-ITX) affects case size and expansion options.
- Ensure compatibility with your chosen CPU, RAM, and GPU.

9. Monitor:
- Size, resolution, refresh rate, and panel type (e.g., IPS, VA).
- Choose a monitor that suits your workflow and visual preferences.

10. Peripherals:
- Keyboard, mouse, headset, webcam, etc.
- Consider ergonomics, functionality, and compatibility.

11. Expandability:
- If you plan to upgrade in the future, look for upgradeable components and a case with sufficient space.

12. Brand and Reliability:
- Research different brands and their reputation for quality and customer support.
- Check reviews and testimonials from previous customers.

13. Warranty and Support:
- Length and coverage of the warranty.
- Availability of technical support and replacement parts.

14. Form Factor:
- Desktop, laptop, or all-in-one?
- Consider portability, power requirements, and space constraints.

15. Energy Efficiency:
- Energy Star certification can help reduce power consumption and lower electricity bills.