I've set Firefox to ask me before setting a cookie on my PC. But I have hundreds of cookies from my months of using IE. Should I delete the cookies that I don't recognize? I hesitate to simply delete all.
Delete them. If your running any kind of spyware checker it's wasting time scanning them. Typically each cookie is less than 100 byte file size, what would that take to load at each visit 2 nanoseconds? I clean my cookies, temp internet files, & history every day. It does make a diff in performance.
If you are using internet explorer, when you have a window open click on the TOOLS meny and then click on Internet options. Hit the delete cookies button. If you are using Firefox, click on TOOLS, then click options, then click on the privacy button and then hit clear cookies.
I think Rom meant to type "Clear history" not "cookies" under the tools / internet options menu. It's a good idea to set your "keep history" to 3 days or less also. The thing I think most tech's miss about cookies, temp internet files & history is it's placement on the hard drive disk. All 3 of these items are the worst at fragmenting a hard drive. At least in the Microsoft OS's. Which in turn degrades performance. I've worked on PC's that have never cleaned the internet files. All I did was remove them and defrag the hard drive and the owners swear I replaced the CPU chip with a higher speed. If you looking for a good tool for cleaning try this one. It's a free full version for 30 days then if you like it it's $30. Click on "downloads" to the left if you want it. http://www.acelogix.com/utilities/disk_cleaner.html
Here is another handy tool...I like it because its freeware. Does an excellent job! http://www.ccleaner.com/