I just upgraded to TCMD 13 from v10. I tried to install over my TCMD 10 folder, and I found that I was unable to enter the registration information in the x64 version. I always got an app-crash, application has stopped working. I was finally able to register by uninstalling the x64 version, installing the 32-bit version and registering it, then uninstalling the 32-bit version and installing the 64-bit version again. That gave me a registered version with the right information in the registry. One question this raises for me is what is the "correct" version to install on Win 7 x64? I don't make use of TCL, in fact I only run batch scripts in TCMD "language". Is this like Word 2010, where there is a 64-bit version but even the vendor says most people should install 32-bit, or is it best to install the 64-bit version?