Search window opening on double click

I am facing a problem in my computer that whenever I double click on folder to open, a search window is opening instead of folder. This is happening in sub folders i.e. My document folder in C: drive. Means I can open the C: drive contenets my double click but on double clicking on My document folders the search window is opening. Same the case is true for other folders also & other drives also (D:, E😀.
I am using Windows XP & having three drives in partition.
Further to add that if I right click on folder (i.e. My document folder or else) I can see a window having first option as search, second as Opening third as explorer etc.. Hence I have to click on second option to open the folder.

Kindly let me know the solution to this problem.😒