Quicktime?
 

Well every video I downlaod that has the QuickTime symbol always plays that retarded video of the teenage girl in red shorts dancing to some song. Any help to get rid of this?

It sounds like you have downloaded some sort of Malware or similar...
Try doing a full system scan with your Anti-Virus scanner and also one with your Anti-Spyware scanners...

If you don't have any, here is a list of freebies...;)
Anti-virus:

avast!

AVG free

Avira Antivir

Antispyware etc:

ad-ware __(FREE)

Spybot - Search & Destroy __(FREE)

AVG Antispyware (formerly Ewido)