Both of these programs are free and catch a lot of stuff that may be lurking around. They always come in handy for second opinions and I would suggest you run each of them at least once a week. I used both of these programs for the past couple of years. You mentioned you ran full McAfee scans twice and deleted the web browsers history. I would venture to say you are OK. Your screen getting stuck is usually related to Internet Explorer. IE8 is recommended but I occasionally have stuck screens also. A friend of mine is an IT specialist for a Fortune 500 company and he always tells me it is the nature of the beast with IE
Thank you k3tg I've done the required scanning and seems that everything is safe for now, all that SuperAntiSpyware detects is one tracking cookie which is the ad.yieldmanager that yahoo places so there are no threats phew...
now there is still that one other question, what shall I do if once again encountering a trojan and in that current moment the screen goes stuck again? just hit the pc's power button or wait till the screen freeze to go away on it's own