When your computer starts acting up, it can be confusing on how to solve it. Doing a search will reveal a lot of websites that tell you "First, download this tool..." NOPE! Skip to the next answer. If it requires a tool, then prepare to make it worse. Trust me.
There are some legitimate ones out there, but if you print the proper steps and sit down with someone else next to you with a little knowledge of computers, the two of you can probably walk through some pretty complicated fixes. Before you do anything though, take the following steps:
Some of these do the same as others, but that's fine. That'll be several copies of different things you can try if something goes wrong. Just, do it, as Nike would say.
You'll need to backup your items onto another hard drive or computer. Personally, I own a Seagate hard drive that I back everything up to. Get what you want, but you need to make sure you have enough space on the external device as you do for the computer itself. In other words, if you have a pot of soup, and you want to put it in a single bowl, you need to make sure you have a bowl as big, if not bigger than your pot. Same principle here.
Once you've backed everything up, which you should do on a regular basis anyway, then you can search for a fix. Do not go to any site that has a name such as IneedWindowsHelp.com or some other ridiculous site. Go for something official from a well accepted website, such as Microsoft's official site. Microsoft has learned how to make searching more helpful, but try using Google to figure it out. If you want to search the entire Microsoft website for something type in the Google search box, site:microsoft.com and notice that there are no spaces there. Then make a space and type what you're looking for. Let's use this one as an example.
Go ahead and click the link above. You'll see the results. Scroll down the page and you'll see that all results are from Micrsoft.com ONLY.
You can use Google to search any website like that. You'd be amazed at what you can find at websites through Google vs. their native search.
So if you're experiencing a slow down on the computer, then you'd use something like site:microsoft.com computer slow down and you can scroll down to see what best fits your situation.
If you're a McAfee user you can try searching their site too, and McAfee is considered a reliable source but on a personal level I cannot stand them. If you're happy with it then that's what matters.
Just remember that simply because someone is giving you instructions on how to fix something, and they sound sympathetic and other users have come behind them and said "Wow that really worked!" be skeptical. Be more than skeptical. Check Microsoft to see what they say and above all else, do not download any tool except from trusted and reliable websites.
If you cannot find the answer at a trusted and reliable website, then may I suggest ask.MetaFilter.com? Now here I am contradicting myself because I'm telling you to go to a site that may have unreliable users, but it's very unlikely and I come back to that in a moment.
As you can see, I've been a user there for eons. If you can view my profile stats, it says I've asked 42 questions. Now here's the rub, it costs you a one-time only membership fee ($5, at the time of this writing). I have personally found it invaluable and when I cannot find an answer anywhere, about anything, I use them.
All that said, it is still not a 100%. It's just that most users who really don't know anything would not be willing to pay even a measly one-time only five bucks to answer a question. Could you get bad advice? Well anything is possible but more than likely it will be sound advice. It is your choice and your decision. I am not saying that you should do it, I am only making a suggestion. The ultimate decision is yours and if you are unhappy with the result then there is nothing I can do about that. Consider this an official disclaimer because you probably know how people are.
All in all, the point is that you really should do all you can to get official advice from a reliable source. When all else fails, have a backup of a place you can ask that you personally trust. If they suggest tools, find another answer. Never download tools unless they belong to Microsoft or McAfee.
Good luck! I hope you all have a pleasant day and may the Lord keep you and shine upon you.