Strange laptop problem.. No idea what to do.. Please help!?

Please read! .. I have an HP Laptop. Yesterday when I turned it on, it went to a black screen and said something about a hard disk? And power or startup? I don't remember. I think it tried to fix itself, but since then, when I turn on the computer, it only stays on for about 60 seconds or so, then restarts itself, and the cycle goes on and on.. It does the same thing in Safe Mode with Networking, but it WILL stay on in normal Safe Mode. Today I decided to try to start the computer up normally, but when it pulls up, turn the wifi off.. I found that that works. The computer will stay on in normal mode as long as the wifi is turned off. A few seconds after you turn it on and it connects to the Internet, it restarts itself. Does that mean a virus is attacking the computer once it connects to Internet? Or something else maybe??

For a while, a Microsoft notification would pop up asking for permission to make changes to the computer, and for a while I said no.. Yesterday I finally said yes to it.. It was Microsoft's Malicious Software Removal Tool, and it said that it partially removed a Trojan, and for me to run an anti-virus software to finish removing it. Which, I could not do, because my Norton 360 will not pull up. I click it, and it does nothing. Sometimes it will pull up for a second, then x's out of itself and won't pull back up. (This is when the WIFI is turned on.) In Safe Mode (without networking, I.e. - no Internet), I ran a full system scan with Norton (the only thing it'll let me do when I click Norton) and it said no risks were detected.

I have tried pressing F8 a few times when it starts up and going to that black screen (to go to safe mode), and tried system repair a few times, but that did nothing. I've tried the one where it goes back to the last settings it worked correctly at, and that did nothing. I have no idea what to do, and don't really have the money to take it to a shop or pay for online help.. Is there anything I can do?

Basically.. Whatever is wrong, only happens when it's connected to the internet. Otherwise, the computer will stay on without restarting or anything. But once you turn on WiFi and it connects to the internet, it restarts itself, and the cycle goes on and on until you turn WiFi off..

The virus or threats which might present in your system and it might be activated when you are connecting to a network or Internet. Once run a Trojan remover software and reset the windows policies and if problem persists you need to format and install OS freshly or contact the service centre they will recover the data or restore you laptop settings to factory settings.