HELP CANNOT UNINSTALL A TRIAL VERSION OF PHOTOSHOP CS4

I am far from being an IT person and am very frustrated in loading this software.   I purchased the student version of Adobe photoshop  CS4 extended and Adobe Illustrator CS4.  My daughter had put a trial version on our computer for an art project. A month later I purchased both Adobe photoshop cs4 extended  and Illustrator 4.  I had trouble loading illustrator until I deleted the trial version.  After deleting cs4 extended, the illustrator worked. However something messed up my printer.  I did a system restore (opps) which messed up my Macafee virus.  I finally fixed Macafee with the help of the customer service.  However, the system restore took off the illustrator and put the cs4 extended version back on.  What a DAY.  I waited a week to try to reinstall illustrator and the CS4 extended.  Now my system will not let me uninstall the trial version nor put illustrator on correctly.  Help--you are my only hope.