Is there a software that I am able to download to upgrade my computer processor speed?

Overclocking a CPU produces heat. That is why you see advertisements for elaborate cooling systems. Maybe the processor won't work at all at that speed. What you need is a new motherboard with the higher speed CPU. That probably means a new power supply, and that means a new case. As long as you are buying a new computer you may as well get a solid state drive (SSD) to match your CPU speed.

Go to newegg.com or tigerdirect.com and discuss your needs with customer service. They will give you a good price on a kit. If you have never put a kit together before, it is nice to have a friend to show you what goes where. I checked newegg and noticed a ready-built model with 3.5 GHz for only 500 bux but it has HDD instead of SSD.