Problem with reading ANSI text file...

I read from ANSI text file (saved from notepad(winXP) with default encoding ANSI).There are cyrilic words in file.I read it with StreamReader("TestFile.txt") and File.OpenText ReadLine()
but there are problems with cyrilic words.incorrectly read only cyrilic words.
if file saved in UTF-8 or Unicode there aren't problems. but i need to read from ANSI encoded text files!
i think i saw in msdn OpenText works only with UTF-8 encodinc files..
i think i need some preencoding ANSI in UTF-8.. or..
Suggest me something..
Thx