Anytime someone gets a used computer the first order of business should be a reinstall of the operating system so you can make it your own.
At this time there is no indication of infection. You can use the recovery partition.
Follow the directions here:How to Perform an HP System Recovery. While the model name shown on the page is different from your laptop model the directions will still work. HP systems generally follow the same procedure.
You will want to choose the option to restore the laptop to factory condition. This should also install all the drivers. Using the recovery system will not ask for your Windows key. Make sure you have the power adapter plugged into the computer and the wall outlet before you start.
If you see something that you don't understand or have questions about anything you can cancel the install and come back here and ask. However, once the install does start you will have to let it complete.
Be patient while the reinstall is taking place. When finished, you can then install your antivirus, firewall, etc. There will be a lot of Windows updates also.
There was a weird program called hamachi which i think may have something to do with it.
This may be what you are referring to. http://hamachi.en.softonic.com/?ab=10
It's a program that allows two computers to connect to each other remotely. It has nothing to do with connecting to a network.
edit to add: you can create one set of recovery disks from the recovery partition. You can access that function by going to Start/All Programs and looking for any HP folders to see where the option is. If not in an HP folder it might be in one that has Security as part of it's name. I've formatted my HP using my Windows 7 disk so I don't have those folders and cannot give you the exact location.
Edited by Queen-Evie, 11 January 2014 - 12:22 AM.