Cruiser, if Adobe opens the document it is in .pdf format, Unfortunately the version of Adobe pre-installed on computers is only a reader, it will not allow you to edit the document. So what options do you have?
The first thing to consider is whether the file is write protected. If it is you will need the password.
The next thing is to find a .pdf editor to edit the file directly, or a converter to enable you to edit it in Word or similar. There are free online tools if you google for Free pdf Editor and that search will also give links to readers with limited editing functions such as Foxit, Nitro and PDF-Xchange viewers, it depends what you want to do. However, if you download software please be aware that some will offer you other things you do not need unless you make sure to opt for a custom install and then untick or decline any offers.
My tip is to go for
AbleWord. It has a clean installer with no offers except for Microsoft's .NET if you computer does not have it - Vista and Win7 have it already installed. It is a small download and will edit .pdfs, even those with images. Most others will not handle images so well.