Cant run Warcraft 3?!?! :( Please help me!

Does someone had that problem? Uhh... every time i run WC3 my antivirus(Avast) show's me that some file called "SIntfNT.dll" is infected by Win32:Trojan-gen {Other} click me and when i click on "Erase" it delete's the file and then it opens a window (CD-ROM drive error.) and it says: Please verify that your Frozen Throne disc is in your CD-ROM drive, then click on 'Retry'. I searched about it at google and i noticed that im not the only one who have that problem but i couldnt find how to fix it :(. Anyway i was wondering if someone had that problem and fixed it.

Thx in Advance.

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