I finally installed Ubuntu in my desktop, but now, when I open Winword files with the text editor, it opens but all the formatting is off. How can I open the file properly?
Try the MS Word replacement, LibreOffice Writer. There are a whole group of open office application to replace MS Office apps.
A text editor such as GEdit is, by definition, only a plain text editor, not a "rich text" editor. Formatting is not desired, since these editors are used for editing plain text configuration files.
A text Editor can and should only be used to open and edit text file. Text file means files which contain only text or characters. Winword files are not text files, because they contains text as well as formatting information, color etc. These are called Word processor file or document file.
What you were doing is, trying to open an word file with a text editor. It is like trying to open word file with Notepad. Some text editors are smart enough to show only the text from an word file. But it is not always the case, most of the text editor won't open the file.
Use LibreOffice which is included in Ubuntu by default. It should also be opened by default if you try to open an Word file. There are other alternative too, such as Abiword, OpenOffice etc.
As the answer of the title of the question, I would say, No, you cannot without clearing all formatting from the file, i.e making it a text file.
If you want to really convert the word file to text file, open it with Gedit and From menu, select File → Save as and give it a name. The file will be saved as a text file.
This link can be helpful:
Besides the difference pointed out in the other answers between plain/rich text, there is also antiword to convert from .doc to .txt
Antiword is a free MS-Word reader for Linux, RISC OS, and DOS. It converts the documents from Word 2, 6, 7, 97, 2000, 2002, and 2003 to text, Postscript, and XML/DocBook. Antiword tries to keep the layout of the document intact.