my 6 month inspiron 1150 started getting really slow recently, it can sometimes take about a minute just to bring up the start bar menu. symantec doesn't find any viruses, im only using 12 of my 40 GB, i tried defragmenting and deleting temporary files as well as error checking and its made no difference.  The only thing which makes it run anything like its old speed is running in safe mode, what does this mean? thanks in advance....