Defragged, now programs won't work

I was defragging my hard drive this afternoon, when I had a power-outage. My computer immediately shut down. After the power came back on, I booted up the computer again and I logged in to find that my background and theme had changed. I didn't think much of it and tried to do a system restore to re-apply my settings. After this, I thought I should defrag the same drive again, and hopefully let it finish this time. After it finished (in about 15 mins) I rebooted and found that any program I tried to open wouldn't open. All of my drivers were reset, and many of the programs are just unresponsive. Upon bootup, many of the programs try to run their installers and have errors. Most of the programs I have on my computer currently do not work. The .exe is still in its location, but upon a double click, nothing happens. I've tried uninstalling and re-downloading and installing programs, but nothing happens.

Did I mess up on this one by trying to system restore after an uncompleted, interrupted defrag?

Also, there are no dates for me to restore to NOW except for today.

Any suggestions/help as to what to do next?

JM