Hello Syed,
There is no way to convert pdf to Word and have it use the appropriate formatting methods in Word. That is because there is no 1:1 correspondence in how things are handled.
The best you can do is what you have been doing, try different programs. Start by simply opening the pdf in Word which will use Word's conversion algorithm. If you can find the source file that created the PDF and attempt to edit that, you will be far ahead of the game.
Documents converted from a different program's file structure will always contain formatting anomalies and often are very difficult to edit. The conversion programs do their best to have the new file look the same when printed but the underlying structure will be different.
What follows is what I've written in the past on this subject at greater length.
Since Word 2013, Word has had the ability to directly open pdf document. However, some pdf documents (from scanners mostly) are really pictures of text rather than the text itself. Just as you can't look under the hood of a picture of a car, you can't edit a picture of a document.
In that case, you need to convert the picture to text. This is a process known as optical character recognition. This is built into Adobe Acrobat and is also in Office OneNote. Most scanner software comes with an OCR component as well. Once you have text, you can edit it with Word.
If you simply want to write on the document (but not in it) you can add a Text Box floating on top of the document layer, whether or not it has been put through the OCR process.
Word documents that have been saved as PDF will not need the OCR process, they retain their text, although not all their Word structure and formatting. Documents created as PDF from other programs will likely be even more problematic.
Finally, documents converted from pdf (or really any other format) to Word can be tough to edit because the conversion process never has a one-to-one matching of how formatting is done under the hood. This means that a converted document will seldom be formatted in Word in a way that uses Word features well for that formatting. An example is multiple section breaks to change margins, where in Word you would simply change the paragraph indent. Margins and Indents in Word. Another example is that Word formatting of text is best done using Styles and those will not be used. It will all be direct formatting. That can make a huge difference in how easy it is to edit. The Importance of Styles in Microsoft Word.
When I really need the document in Word format and intend to do much editing, I create a new Word file and paste the content into it as plain text. Then I format it to match the original using Styles for the formatting as much as possible.
