Most of the systems out there are not running at their full potential performance. Any system should be properly optimized to be able to work efficiently and effectively. An optimized system can load programs faster, load more programs at the same time, and crash less frequently.
Tip 1: Upgrade Hardware
If you are looking to increase the performance of a computer, from my experience, the parts of any computer that are worth upgrading are:
- Memory
- Hard Drive
- Graphic Card
The memory is the easiest and the most effective way to increase the performance of a computer.
Each hard drive has a certain access speed and it's often referred to as RPM, which stands for the number of round spins per minute. (e.g. 4200RPM, 5400RPM, 7200RPM, 10,000 or 10K RPM) The more the RPM number, the faster the hard drive is.
When your computer boots up, it reads the OS files on the hard drive in order to load into the operating system. When you launch a program, the OS reads the hard drive for the program files. Therefore, the faster the hard drive's access speed, the faster the OS or program loads.
Graphic card is really optional; it depends on what programs that you run on your computer. If you do 3D rendering or movie editing, you would need a high performance graphic card. Same thing if you are into games that require high graphical performance. Otherwise, for regular office tasks, on-board graphic card is more than enough.
Tip 2: Disable Unnecessary Hardware(s)
Here we are referring to the hardware(s) that you can disable in the BIOS.
If you are working on a person's computer, make sure you ask him what hardware(s) he needs to use.
For example:
- Floppy Drive
- Parallel Ports
- Serial Ports
- Firewire / 1394 Ports
- SCSI Ports
- Modem
If the person has a PCI or external sound device installed, it's also a good practice to disable the system's onboard sound device. Same thing with network devices (referred to as NIC) and graphic devices...etc.
Tip 3: Uninstall Unnecessary Programs
Go to Control Panel and run "Add or Remove Programs" for XP or "Programs and Features" for Vista. Uninstall what's unnecessary.
"Add or Remove Programs" Screenshot for XP

"Program and Features" Screenshot for Vista

Tip 4: Disable Unnecessary background programs and services
Go to Start Menu and look in the "Startup" folder. Delete what's unnecessary.
Go to Control Panel => Administrative Tools => System Configuration. In the "Services" and "Startup" tabs, uncheck what's unnecessary.

Tip 5: Disable Visual Effects or let System Adjust for Best Performance
Go to Advanced System Settings. Under Advance tab, click on Settings under Performance. Disable unnecessary visual effects or let system adjust for best performance.
Take Control
Do not rely on Windows Optimizing software(s) to optimize your windows. Take control of your computer.
P.S.Don't forget to defragment frequently

