I don't know what's wrong with my computer ?!

Okay this is my first post , so I'm hoping this is the right place for this...

About 3 days ago my computer starting going reallyyyy slow and it will not allow me to send picture's in my email. If I try it freeze's and the only thing I know to do is Ctrl + Alt + delete (I hope it's not a bad thing to do that confused ). Anyways I started trying to figure out the problem and was sent to this website by someone on another forum. I read the page "Basic computer maintenance everyone should do " by Major Attitude. I know it's probally really bad, but I have never done any of the things listed. So I went ahead and removed some old programs and start-up items, then I downloaded and ran CCleaner. I also downloaded Diskeeper Lite, however when i try to run it I get this pop-up...
To find out what shape your disk is in, simply highlight the drive in the Diskeeper display, then click "Analyze." The results of this analysis will show you how much fragmentation and how much performance degradation you are suffering from. Once the analysis is done, click “Defragment Now” to start a manual defragmentation job. Diskeeper Lite includes Smart Analyze ™ and will automatically monitor your disk and alert you when file fragmentation reaches levels that affect system performance or potential reliability and uptime issues
I have tried to do this but when I click "Analyze" nothing happens except that it takes the "Defragment Now" button away. Could I have downloaded it wrong ? or maybe it's just not working because my computer is so slow ? I hope all of this makes some sense and someone here can help me.

 

You can look here FAQ, if u running a manual scan n another process is running it will not work.

http://support.diskeeper.com/support/diskeeperfaqs.aspx?Page=5&Subpage=2&cust=1&RId=1&CId=1&SId=2

 

"You can look here FAQ, if u running a manual scan n another process is running it will not work. "

I read the FAQ's, but how do I know if another process is running ?

"Try using another defrag or the one with windows."

Is it okay to download another one ? Do I need to delete Diskeeper Lite ?

 

Just a note - you don't delete programs you no longer want? Correct thing to do with a computer is to delete files you no longer want but uninstall unwanted programs. Deleting programs can lead to problems with your computer being slow or or performing incorrectly. I saw one once where the monitor initially worked and then kept going into standby before the computer fully booted up because someone deleted programs galore instead of uninstalling them.