It's cheap though and from what I understand it works similar to the program you used to have.
If you buy the Testors decal kit they include a sample of their decal maker software (the full program is $8.95), but I've not heard many praise it's virtues. I've not seen any specific decal making programs that were of any use beyond maybe providing some useful clip art.
You can find short video tutorials on youtube to walk you through table use if you are not familiar with setting them up. Tables take some practice if you've never used them but not too bad. This allows you to control where on the page they will appear much like the business card programs do. The you insert pictures into the blocks and resize them to your needs. Well with word, you simply open a table with columns / rows set to provide the size blocks you need. Maybe I should try "Word" or something first. I was hoping I could fill up a disc with images & then take them to an Office Max or the like & have them printed on my decal paper on a Laser printer. I had seen actual "decal maker" software on the net & was wondering if anyone had tried them. I also had issues with shrinking the images too much & having them wind up far too distorted. Of course, with an inkjet printer you have issues with the ink coming off so they need sealing.
I would just download images from the net, shrink or reshape them & print them on my inkjet. Was still using it until I purchased a new computer. I've had a little experience printing up some decals with my old "Broderbund" Print Master Card making software from probably 25 years ago. That's a little more to take in than this 51 year old basically computer illiterate brain can handle! I'm looking to keep it pretty simple, & while I do want nice looking decals, they don't need to be perfect. The other issue is the decals are basically transparent unless you use special printers, so you need to use them over light colors or use white decal paper which creates its own issues. Making your own decals is really fun and opens up a lot of new options, but it can be a lot of work. Something simple like a warning sticker on a commercial truck which is just text on a brightly colored polygon "Don't put your tongue in the fan belt" is pretty easy though, maybe 10 minutes. Doing something complex like a city or state seal might involve 6 or 8 hours of drawing time.
I've been using Corel Draw about 10 years now and I'm still learning how to do things. The real downside to most vector programs is they have a very steep learning curve and are not particularly intuitive for most people. I shrink it down to 1/2", 1" or whatever as appropriate for the model it is going onto. I frequently work on a decal at about 5-6" which is big enough to see the details well, but small enough that I don't have to pan around the screen much. This not only allows you to rescale for different uses but also allows you to work at a conveiniant size. Vector based programs use reference points instead of pixels so you can take a small image and blow it up into a huge image or take a large image and shrink it down to a postage stamp with no loss of quality. Large changes in size can result in major distortion issues. Raster based programs use tiny dots to make an image, so when you enlarge or shrink the image it actually changes by adding or subtracting pixels. Vector based programs are different from the more common (and generally much cheaper) raster (aka pixel) based programs like Microsoft Paint that you get free with many computers. Inkscape is a free vector drawing program, I have no experience with it, but hey it's free what do you have to lose. Sometimes you can find an older version on ebay for much less, and they really don't lose much for our use vs getting the latest version.
These are not cheap programs ($200+) but if you are a student (or have kids in school) you can use them to get a cheaper student version for about 1/2 price.
These are what most professional / hard core do it yourselfers are using. The higher end is to use a vector based drawing program like Corel Draw or Adobe Illustrator. The big advantage to this method is it has a fairly shallow learning curve and uses programs most people already have on their computers.
This is also used by many to make license plates, books or magazines to lay on a seat in a car etc. You will get some distortion, but by starting with a good large image you can get a respectable result. For fairly simple stuff you can simply take a good quality image and shrink it, then use a word program like Microsoft word, open office etc to layout your sheet.