Temp folder can be deleted, no probs at all.
techmanc way is useful and effective, no doubt about it. However, if you do not understand what is it, u better use a little bit simple way while u learn how to use autoruns. Here are 2 steps :
-Use disk cleanup(start menu > accessories > system tools > disk cleanup) there are several boxes, tick anything that you want to delete, click ok.
-Use ccleaner(go to www.download.com)