How to delete file in

How to delete file in "c:/windows/system32 " folder??

I visited this forum a few days ago, and when I click on one link to a computer article in one message (the address shows that it is a website in China), it popped out one small window with charators that nobody can read, I closed it immediately. But after that day, I notice there is a shortcut icon added on my desktop. The short cut points to

c:/windows/system32

I went to this directory and found two files were added, one is "idnMail.exe" the other is "idnMail.dll"

I tried to deleted it but failed as these files are "read only".

Any idea ?