[misse30]

I need some help i have something on my computer that won't let me do anything. i can't open any pages to get the hijackthis program theres a box that says the page is being blocked by malware or spyware and i keep getting popups to download virusburst and there is a flashing ? mark in the taskbar that pops up a box that says critical system error, where do i start to remove this

thank misse