If the client sent the file in another format, not compatible with MS Office, ask him to send the file in source format, if he can't, then do the following:

PDF format:

- check it you can copy the whole text from in into DOC
- if not, ask the client to send the file in source format, like DOCX or PPTX, or else
- otherwise recognise the text using Adobe Acrobat Pro or Abbyy FineReader and save as Doc file (you will use it later while calculation)
- open in MS Word and see the number of words

Picture like JPEG or PNG:

- recognise the text in Abbyy FineReader and convert it to RTF or DOC
- open in MS Word and see the number of words and use it for further calculations

Other format, e.g. for InDesign or other special programme:

- check if it's compatible with Trados or other CAT-tool
- if yes, make a project and make analyze the file