Solved: "failed to create empty document" error message

I use Windows XP. I installed and ran the Avast grime fighter and then found two of my programs - one for tax preparation and one for backing up to an external hard drive - won't "open". Instead, I get the error message "failed to create empty document". I uninstalled the programs then reinstalled them, but no change - I still get the message. I saw, by googling the message, that it may have something to do with a windows registry file, but I really don't understand what that is or how to get to it or how to fix it. I contacted the Avast folks and they said they could put me in touch with their microsoft folks for $180! I am at a loss as to what I should do. Please can anyone help me figure out what to do to get these programs to run? I really need the tax program especially. Thank you.

This is the text from running the TSG SysInfo utility:
Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows XP Professional, Service Pack 3, 32 bit
Processor: Intel(R) Core(TM)2 Duo CPU E7400 @ 2.80GHz, x86 Family 6 Model 23 Stepping 10
Processor Count: 2
RAM: 3036 Mb
Graphics Card: Intel(R) G45/G43 Express Chipset, 1024 Mb
Hard Drives: C: Total - 476899 MB, Free - 426176 MB;
Motherboard: Dell Inc., 0P301D
Antivirus: avast! Antivirus, Updated: Yes, On-Demand Scanner: Enabled

 

At first, I did not want to try this, as I ran the program more than a month ago - before I noticed the problem. The fix you recommended says it can only be done within a week. But then I thought what the heck, and tried to do it. Unfortunately, the option to "undo last scan" did not appear under the big green "begin grime fighter" button.... perhaps because the option to undo was time-barred.

I am appreciative of the suggestion; do you have any other(s)?

 

My dearest "managed" (Allan) - I cannot thank you enough! I was totally lost and very worried, but your suggestion helped me fix the problem, and I now have access to the programs I need! Saying you are wonderful isn't enough, but it's all that comes out of my mouth! Happy Valentine's Day from a very grateful Yank!