Installing or running Toad gave
"C:\Windows\System32\msxml3.dll is either not designed to run on Windows or it contains an error. Try installing the program again using the original installation media or contact your system administrator or the software vendor for support"
Causes for this error are listed in the following site.
http://pcsupport.about.com/od/findbyerrormessage/a/msxml3-dll-not-found-missing-error.htm
1. Run you a virus scan on your system
2. If the virus scan didn't resolved the issue or picked up nothing, the open command prompt and ran sfc /scannow
For more info on sfc /scannow or warnings concerns sfc /scannow please consult Microsoft.