If you make a picture or words in Wordpad or notepad, is it possible to somehow format them into a jpeg file on your computer so as to use the image as a jpeg later on? Changing the file name to .jpg doesn’t work… 
You could take a screen shot.
How?
Assuming you are using Windows…
Pressing the PrtScrn key will copy the an image of the current desktop into your clipboard. Use Alt + PrtScrn if you only want the currently active Window.
You can then paste the image into any graphics software and save it to jpeg format.
If you don’t have any fancy graphics software (Photoshop, etc.) you can use the Paint program which comes with windows and use “Save As” to save in jpeg format.
Open the Wordpad/Notepad document so that the image you want to capture is displayed on the screen. Hit [Prnt Scrn] (may require a combination of keys, depending on your computer). Open MS Paint. Click Edit Paste. Make sure your “toolbox” is displayed (View Toolbox). Use the Select tool (dashed line rectangle) to select the specific portion of the screen you want in the image file. Click Edit Copy. Click File New (and select No when it asks if you want to save it). Click Edit Paste. Click File Save and enter a filename. You will now have the image you desire in bitmap format (*.bmp). You will a different graphics program to convert the bitmap to JPEG, and just about any basic graphics package (even free ones) will do this. Contrary to FatBaldGuy, MS Paint doesn’t save in JPEG format.
Depends on version. The WinXP version of MS Paint will save in (1-, 4-, 8-, and 24-bit) BMP, JPEG, GIF, TIFF, and PNG.
There are also utilities that can do this for you such as http://www.zan1011.com/jpg.htm. I think they give you a thirty day trial.
Another more convulated way that I use (I am too cheap to pay the $30) on XP is I print to Fax (it was installed by default on my WinXP, you can probably add it under Add/Remove Programs -> Add/Remove Windows Components). I have to click next three times and select a fake phone number to fax to. At the last screen there is a preview fax button. I click that and I have the option of saving as an image (bmp, jpg, tiff, gif, png), editing in paint, or adding lines, highlights, or my own text.
The advantage is: its free, I get the whole page(s).
The downside is: lots of steps, it is black and white.
Yeah paint worked. Thanks
Changing a file name’s extension does not change the properties of the file. It only changes its name, and as you found out, renders it as an invalid file with the new extension. In order to create a .jpg graphic file you need to do it using a graphics tool.
The suggestion to take a screen shot of the document works, but it’s not elegant.
Finally, if the idea is to make a graphic image of text, this is very customer unfriendly. If you plan to put this image on a web site, don’t. You will lose more than you ever thought you would gain. Creating image buttons with text is one thing; doing the same for anything more than that is not good.
Somebody made a free software called “jpeg book” for the Sony PSP. It converts text documents into jpegs. However, I’ve never used it, and it might only convert them to jpegs that will fit on the PSP (280 x 420 or something like that). It’s worth looking into, if only for the fact that it’s free.