I know this sounds crazy, but my i5 750 seams sluggish compared to my e6500 when opening word etc. The e6500 opens word instantly, but the i5 750 takes 3 seconds to open word. when working with video or heavy loads the I5 smokes the e6500. Basically it's when I switch our open programs.
Your hard drive is going to determine how fast your programs open.
You'll need to clean (ccleaner) your hard drive and defrag (auslogics).
Reformatting helps if its been a long time.
Upgrade your hard drive! SSDs are becoming somewhat affordable, especially as boot drives. I just bought a 64GB (abit, $115) w/ sandforce rated @ 280MB/s read 270 MB/s write and everything is just about instant. 10k RPM VelociRaptors are fun too, though not quite as fast as SSDs, they still make great drives for games/big workloads.