All programs say "not responding" then my computer crashes-please help

When I turn on my computer, everything seems fine at first. After I open a program, the program usually doesn't run. Programs I've tried include iTunes, Google Chrome, and simply trying to open files stored on my computer.
After about 30 seconds, whatever program I'm using says "not responding" then crashes. After that happens, I can't even open the dock to shut down, restart, etc.... I can't open the file folders on my desktop, the entire operating system becomes unresponsive, then eventually crashes. I have to shut it down by holding down the power button.
I have tried restarting it several times. I have managed to open my computer in "safe mode with networking," but I need to be able to access other programs on here, and I would just like to be able to use it the normal way so I have my preferences, wallpaper, sound, etc.... In safe mode, I ran Defrag, deleted several unnecessary files, and deleted the computer game I recently installed that I thought might have been causing the problem. I don't have any other games on my computer, but I do have video files, music files, Photoshop, Illustrator, VLC Media Player, Chrome, Firefox, Microsoft Office, and some others, I can say which ones if anyone needs to know in order to help.
I found a thread where someone recommended going to the command prompts and typing in "sfc/scannow" and I did that, but it didn't work. I've tried doing system recovery but that didn't work.
Can anyone help me identify the problem and tell me what to do about it? I'm not very advanced with computer knowledge and I don't know a lot of terms, but I can answer any questions you have about what my computer's doing if that can help.

tldr: My computer doesn't work outside safe mode and I have no idea how to fix it, and I am a beginner with computers. Please help.

I have had this happen a lot, especially with Office '10 programs. I'd suggest that as soon as it stops responding, check the time. Use safe mode and begin to gatheer information by going to the event viewer and tracking down every error listed around that time. Hopefully you'll see a pattern as to thee cause(s).

Also run chkdisk just to be sure there's no corrupted data.

I ran CHKDSK, it took a long time, and I wrote down the results:

41 repairs records processed
1302 large file records processed
0 bad file records processed
0 EA records processed (file verification)

208354 index entries processed (index verification)

0 unindexed files scanned
0 unindexed files recovered (index verification complete)

160512 file SDs/SIDs processed (verifying security desciptors)

23922 data files processed (desciptor verification completed)

34730872 USN bytes processed (verifying USN journal)

160496 files processed (this took about 2 hours and was verifying file data)

verifying free space: 9011502 free clusters

I don't know what most of it means, but I don't think it said any data was corrupted.

I think I typed it with the space, but the scan ran and didn't find anything. Is powering off illegally just holding down the power button? Because I've done that every time. I don't know the password to get into repair mode.

I'll try the event viewer if I can, and hopefully I'll find the errors. What do I do if I know what the errors are?

It looks like one error that has happened a lot in the past few days, and looks like it could be every time I start up my computer, is one where the source is "perfnet" and the event ID is 2004. I am going to try SFC /SCANNOW again without the space. Thanks for the help so far.

Question: Have you attempted to do a system recovery?

If not go to safe mode then go to "Control Panel" and bring up "Recovery." At this point choose a date prior to the time you started having problems.

Also if you have a Malware problem run that to see if you have some nasties running around on your OS.

Just some thoughts; good luck.

BTW, always back up your needed files prior to making any changes to the System.

I ran sfc /sannow again, with the space, and got the same result: "Windows resource protection did not find any integrity violations"

First I am going to try to do the Option 2 of DSKCHK, I used Option 1 before. If Option 2 doesn't do anything, I'll take a stab at System Recovery. Thanks again.

One question: In the command prompts, do I type: chkdsk[c]:/f
I just want to make sure I'm getting the letters'symbols right. If this isn't right, what exactly do I type?