The fact that your game was crashing while SimPE wasn't installed suggests a problem in the game, and from from what you describe I would suspect that Veronaville has become corrupt. Do you have a backup of it kept somewhere else? If so, leave it there for now. We need to solve the other problems first.

There is a FAQ at MTS that will help you track down the problems in the game. Rather than repeating it all, I'm just going to link you to it. http://www.modthesims.info/wiki.php?title=Game_Help:Game_Problem

As I said, I think your Veronaville may be corrupt. Once you have the game working again you may want to restore the old backup of Veronaville, if you have one.

As for the SimPE problems, you need to set the program to "run as Administrator" as well as running under an Administrator account. This is not a default setting that Vista or W7 has. You have to manually set it yourself. It accesses files that "belong" to another program, and you really don't want that kind of activity going on without your knowledge. (Especially as that is one of the things that viruses and trojans do.) If it got as far as opening, but not saving, that might be the trouble.

It also isn't fond of corrupted files. If Veronaville was already corrupt, it might have been corrupt enough not to be able to save. (Assuming that you were working on it when the problem was occurring.)

Version .73 doesn't have a built-in installer. Make a brand new folder for it.  (This is true any time you install it.) That folder can be in Program Files, or anywhere else you care to put it. (You could even have it on your desktop if you really wanted to.)

Then unzip the download into that folder.

Now locate the .exe file. This is what you run it with.

If you have placed the folder somewhere logical, like Program Files, you might want to make a desktop shortcut to the .exe file. (With W7 or Vista, a shortcut is also handy because you can set the properties to automatically Run as Administrator, and avoid having to right-click and select that all the time.)

As for fixing Veronaville, I'm afraid that restoring the backup is the best way. If you knew what part was corrupt, you might be able to salvage just that file from the backup and keep the rest. But if you don't know where the problem is, randomly replacing files and seeing if it is fixed now would take a lot of time and risk making an even worse mess. If you really want to try that, I would definitely recommend making a backup of the bad neighborhood before testing.

Personally, I would restore the backup, make sure it works,  then play something else for a month or two. Then the lost progress won't be as much of a shock, and you can be happier about the progress that wasn't lost. That worked for me several years ago when I was helping my son with a game of Might and Magic and accidentally saved his game over mine. My backup save was made when all my characters were 20 levels lower and I was going to enchant some items to try to get something good out of it, but wanted to be able to go back and try again if I got some real junk. After a month or so of not playing, I stopped being upset about losing that nice equipment and those 20 levels, and was just happy that I wasn't going back to the beginning again.

(I hope you have already determined that the problem isn't a bad hack, or other piece of bad CC? If everything is fine with all CC gone, you just need to get rid of a download or two. Of course, finding the bad download is a real pain sometimes. ;) )

You should have the Net 2 Framework if you are working with Vista or W7, as that is -supposedly- part of Net 3.5.  You don't need to be the only user, just running it on an Administrator accout, and using "run as Administrator".

If something is missing from the download, you would have expected someone else to have had trouble before now.

If your download was corrupt, it isn't likely to have been corrupt again when you redownload.

I'm running low on ideas. Run it again, and this time when you get that error report select the whole thing, copy it, and paste it here. Then I can ask Peter to read it and see if he can figure out what's wrong.