After leaving my machine alone for a couple weeks, I returned to do some Qt-using-VC10 work. The first sign of trouble was a QtCreator error about "cl" not being recognized, which led me to discover that C:\Windows\System32 had somehow been removed from PATH. The inability to identify the "reg" command was making vcvarsall.bat fail to set VS100COMNTOOLS, as described here.
The aforementioned thread directed me to this, which suggested simply adding C:\Windows\System32 back to PATH.
However, my troubles were not over. Once C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\vcvars32.bat (a script invoked by vcvarsall.bat) was able to invoke "reg", it failed to find the key necessary for setting VS100COMNTOOLS. The failure occured at the following line:
for /F "tokens=1,2*" %%i in ('reg query "%1\SOFTWARE\Microsoft\VisualStudio\SxS\VS7" /v "10.0"') DO (
@if "%%i"=="10.0" (
@SET "VS100COMNTOOLS=%%k"
)
)
The output I got from vcvars32.bat (with unsuppressed output) was:
C:\Users\Bob\Desktop>for /F "tokens=1,2*" %i in ('reg query "HKLM\SOFTWARE\Micro
soft\VisualStudio\SxS\VS7" /v "10.0"') DO ()
ERROR: The system was unable to find the specified registry key or value.
Sure enough, the indicated location in my branch does not exist. The relevant subset of my registry tree looks like this:
HKEY_LOCAL_MACHINE\
SOFTWARE\
Microsoft\
VisualStudio\
10.0\
Debugger\
11.0\
...
9.0\
...
Debugger\
...
Does anyone know what is going on here? Could the automatic windows updates after my two weeks of absence be responsible? How do I fix my system so vcvarsall.bat can manage to set VS100COMNTOOLS?