deleted files not in recycle bin

I am having MSI laptop with 25GB HDD and running on Windows XP. I was cleaning up my C drive by deleting unwanted old files and folders kept in my documents and all. By mistakenly I also deleted few folders containing very important images. Usually I do right click delete or by delete key on the keyboard, never do Shift+delete.

Now the problem is that after deleting the images folders mistakenly I went to recycle bin to retrieve them back but surprisingly there were no files or folders available. Let me tell you that I have set it not to permanently delete, also there is more than 100 GB space left on my C drive and as I said I never do Shift + delete.

Can anyone help me retrieving the same ?

Before we start any hardcore troubleshooting I want you to check your recycle bin properties again if you have check marked the option “Don’t move the files to Recycle bin. Remove files immediately when deleted”

Right click on the recycle bin. Click on properties. Uncheck "Display delete confirmation dialog." Click on Apply. Click on OK.