I lost my windows 7 gadget. What should i do?

I have Windows 7 Ultimate 32 bit in Dell Inspiron 1525. I replaced previous vista Home basic and am using 7 for about a year. Few weeks ago i found gadgets automatically got loat from desktop. When i run them, a small white square like icon appears in desktop with no use. what to do?
I do not have backup or system restore.

A few more errrors came during its work spontaneously. like i dont have help content at all (since begining). And my windows explorer opens each folder in separate window even when i corrected it in folder options. Any help, plz give me.