My computer has 10000 viruses

Macintosh
Starting up in Safe Mode

To start up into Safe Mode (to Safe Boot), follow these steps.
1.Be sure your Mac is shut down.
2.Press the power button.
3.Immediately after you hear the startup tone, hold the Shift key.
The Shift key should be held as soon as possible after the startup tone, but not before the tone.
4.Release the Shift key when you see the gray Apple logo and the progress indicator (looks like a spinning gear).

After the logo appears, you should see a progress bar during startup. This indicates that your computer is performing a directory check as part of Safe Mode.

To leave Safe Mode, restart your computer without holding any keys during startup.

I installed (AVAST!) but the free version can only do so much the majoirty of it was

Email spam

Internet spyware and malware

Junk files

Fragmented disk drive

I need to download and buy the top notch one.

How do I speed up my PC?

Its running very slow.

this is pretty serious id take that to a computer shop or something they could fix it but it would cost $ maybe :-\

Well im using my dads computer until I get my new PC!