I have a dell Dimension e520 desktop computer with windows xp media center . I think I have a virus /malware .when i turn on my computer it is very slow coming on so that i can use windows .I am using internet explorer ,it is very slow getting up the google homepage ,when i have a webpage or a number of windows open it can work find for a bit then it freezes or crashes and i have to use the task manager to close the programs ,also the screen writing has changed size and the background colour of the start menu and system tray has some how changed .I dont think it has anything to do with the memory because i dont have to much stored or installed on computer .If i could get some help or advice that would really help me out .thanks!