boolGetItemInstallInfo(PublishedFileId_tnPublishedFileID,uint64*punSizeOnDisk,char*pchFolder,uint32cchFolderSize,bool*pbLegacyItem)// returns true if item is installed
boolGetItemInstallInfo(PublishedFileId_tnPublishedFileID,uint64*punSizeOnDisk,STEAM_OUT_STRING_COUNT(cchFolderSize)char*pchFolder,uint32cchFolderSize,bool*pbLegacyItem)// returns true if item is installed