My Win7 is running so slow....!!!!

Hello to all,
My Dell Vostro 1510 (32bits) is running Win7 Home Premium.
It has no more guarantees from DELL, and I can’t get any help from them.
It used to be a fast and reliable laptop. Now it is running so slow that makes its use almost negligible.
I already spent all the knowledge I have, which is not great.
It has a 25O GB HD with 70 GB free space.
It is defragmented. I made the memory tests, and the results are OK.
No virus was found by ESET NOD32 AV.
I have run sfc /scannow and chkdsk as well, and both found no problems with the system.
What other tests are suggested to be done, and what may be wrong with the system?
I appreciate any help you can give to me.
I wish all of you a Merry Xmas and a Happy 2016.
Cheers,
Flores

Hi,
Use Clean boot,
Troubleshoot Application Conflicts by Performing a Clean Startup
Click Start and type in the search box,
msconfig
Click on the suggestion on top or hit the Enter key,
Go to the Startup section and take some screen shots for a complete list,
Go to the Services section and on the bottom left Check the box to Hide All Microsoft services,
Repeat the screen shots,
See the links above my signature on how to take and upload screen shots here,
Cheers.