Dll file icons in System32 folder are different than others

Good Afternoon

I just want to know if I must be worried about what happened to my computer recently. I have windows XP, while checking my files I noticed that some dll files looked different from the other dll files on my computer: the traditional look is a pair of “gears” one of them green and other of them orange, but these dll files looked like two small gears: one yellow and another one white: completely different!. This looked strange so I decided to check my windows folder and system32 folder: The system32 folder dll files had this strange icon too!. Up to the date I haven’t noticed anything else yet. Is this a virus?. What can I do to solve this problem?.

Thank you.

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