Windows rebooting @ startup

[Androme]

After installing Sygate Personal Pro last night and shutting down, it was to my horror that upon restart the PC crashed and keeps on doing so. Basically, the computer starts up - now when it gets to the login screen - regardless of whether I login or not, the PC will go black after 5-7 seconds displaying a message "no signal" then the system will restart and the same process happens.

I checked a site off Google and it said to check my voltages which I have done alas, no help.

Thanks all.