You must have (buy ?) Adobe's PDF writer.
Portable Document FormatPDF is a file format within Adobe Acrobat. Any file with an extension of .pdf can be opened with Adobe Acrobat.
Adobe Acrobat
Yes, if you have Adobe Acrobat (not the free Adobe Reader) installed on your computer. There is also 3rd party software that will convert the .pdf file extension to a file type you can edit without purchasing Adobe Acrobat.
which format file you want to save as pdf file Try some converter such as office to pdf converter not need adobe
I think what you mean is to change the resolution of the PDF files? 'Cause I found this : "e.g. a 300 dpi printer has "pixels" that are 1/300 inches in size, while a 72dpi monitor has 1/72 inch sized pixels. A 100x100@72dpi image on a monitor would have to be printed out at about 417x417 printer pixels to have the same apparent size (300/72 = 4.16666)" So if it does, here is the solution: In Adobe Acrobat, "Edit > Preferences > Convert to PDF", choose the file you want to change, select "Adobe PDF Settings > Editing > Standard" and then Edit again to change the resolution. May this will do some help.
A computer file with the ending .pdf - you open it with adobe reader or adobe acrobat. The file can contain a document or pictures
PDF - Portable Document FormatThis file format is created by Adobe Systems for exchanging of documents
PDF is a file format - Portable document format. You can open it in Adobe Acrobat Reader.
It sounds like the file you are trying to read has become corrupted somehow. Or there is something wrong with your Adobe installation. Try reading a different pdf file and see if it works, if it does, then the first file is corrupt. If not, reinstall Adobe.
Download and install Adobe Reader.