Value of 3rd Party Utility Programs

I'd like to hear some views on whether or not 3rd party utility programs, and particularly Advanced System Optimizer, are of value or a potential problem. When I was having problems with an older Dell 531, I tried using ASO hoping that cleaning up the registry and clearing out file fragments would help. It didn't. If anything it seemed to create more problems. After a 'cleaning' I wouldn't be able to reboot and would need to do a system restore. Now to be fair to ASO, it turned out there were hardware problems and I ended up building a new computer.

The reason for the note is that I can see the potential value of programs like ASO in cleaning up things regularly. However, my initial experience leaves me a bit concerned that programs like this might, in fact, do serious damage. Any advice on whether programs like ASO should or should not be used would be appreciated - with Windows 7 X64. Also, any thoughts on the value and effectiveness of ASO - or better alternatives.

You're going to get quite a few responses on this one, so with your previous experience with these programs I think you already have the best answer... first hand experience.

Here's some more threads,

Is a registry cleaner needed for win 7 64-bit

The best registry cleaner, which one?

I used a Registry Cleaner

Yea, I kinda suspected that was the case. This topic does seem to come up periodically. I just wanted to check, because when I tried ASO before there were definitely other problems with the computer, but I did feel the ASO program made things worse, not better. Anyway, my new computer is working well; Window 7 X64 is running without any significant issues. I think I'll leave it alone and stick to Windows maintenance tools.

Thanks for the reply.