Should I run Ccleaner if browsers are slow?

I've got some options here. Which one do I choose?

Kaspersky Rescue Disk. Graphic Mode
Kaspersky Rescue Disk. Text Mode
Hardware Info
Boot from Hard Disk
Reboot
Shut Down

Can I run this on my cousin's old Windows Vista PC? It won't boot into the normal operating system. Will it fix it?

No threats were detected on my system.

Okay

Well. It was our old desktop. His mother knows how to fix computers better than I do. But, they've been so busy with getting there new house ready. I figured it might help if I run it on the computer to see what it detects. Because, more than likely it's a bug or something. Vista computers were known for getting bugs and viruses in their time.

Unfortunately, I don't have one.