Hello & Welcome to JustAnswer. My name is XXXXX XXXXX i will do my best to assist you.
The USB ones are better since they are portable and can work with any system.
The 300mbps is better and the best.
I would recommend you to get this one by Clicking Here. It's a 300 Mbps / Wireless USB.
so the pci ones doen't work faster or better than the usb ones?
My computer is acting up and slow so I checked "Processes" on Windows task manager and found out svchost.exe's CPU is about 50 and system idel process is about 50. When I check the Performance on windows task manager, CPU usage shows as about 50% which is making the computer slow. Please advice to fix this issue and what is svchost.exe? virus?