If the web pages are taking a long time to load, then it's your connection. Are you using wireless? If so, try an ethernet connection if you can. Also, do a speedtest.net (let it find the server itself) and post it here.
Also on task manager, on the processes tab, at the bottom it should say:
Processes: X, CPU Usage: X, Physical Memory: X, let me know what they say.
Also, download WinDirStat:
http://downloads.sourceforge.net/project/windirstat/windirstat/1.1.2 installer re-release (more languages!)/windirstat1_1_2_setup.exe?r=http://windirstat.info/download.html&ts=1369838519&use_mirror=switch
It tells you what's taking up space on your hard drive. Could be a large hibernation or pager file clogging your hard drive and ultimately slowing everything down. Screenshot the results.
And stop deleting your cookies weekly. Cookies use very little space and unless you use IE they don't slow you down (unless you've never cleared them in like 10 years
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- they don't do any harm and can actually be of use.