When i used a pc, i found that to keepit running at peak , i needed to defrag at least every other month, clean out all cookies weekly unless it is set to clean cookies each time its turned on, and run an anti-virus software monthly. The best way i can discribe defrag is when programs and files are put on a hard drive every time you delete a partial program or file it leaves an empty space, When you add a new program or file it automaticly fills the spaces so the program is in fragments, so the computer searches for the fragments to run the program and this slows the computer down, using defrag finds all your programs and files and puts them back in order so the computer runs faster. I run an apple with auto defrag, and told it to empty cookies every time its turned on. <<My computer runs slow cause its 15 years old. I love pcs for gaming, but macs for everything else. Also look into your internet provider, it has been in the news lately that some providers are slowing down their speeds at peak use times to get people to buy the speed upgrade. verizon, and att has been under investigation for doing this. I also agree that installing a solid state drive is the way to go, i'm looking forward to a new mac next year with all solid state drives, i think thats the way to go.