Sergey,
You may try the GetAppPath() method of the ffc registry class, although I suspect that it will return the PDFReader:

loReg = NEWOBJECT("FileReg", HOME() + "ffc\registry")
lcAppKey = ""
lcAppPath = ""
loReg.GetAppPath("PDF", @lcAppKey, @lcAppPath)
?lcAppPath

>>Sergey,
>>
>>I don't have PDFWriter. I guess you've looked at AGETFILEVERSION() and/or the registry?
>>
>>>How to find out programmatically what version of Adobe PDFWriter is installed on PC?
>
>I didn't find anything about the version in the registry but AGETFILEVERSION() should work. The question is how to find where PDFWriter files are located.