Looks like 'Talend-All-r63143-V4.2.2-windows-installer.exe' doesn't work well with Windows 7.
Solution seems to be:
1) Use the manual install zip file 'Talend-All-r63143-V4.2.2.zip' instead of 'Talend-All-r63143-V4.2.2-windows-installer.exe'
2) Unzip it with 7-Zip, not with Windows Explorer
3) Unzip it to a root drive, e.g. 'C:\Talend-4.2.2\studio\', (I suspect Talend isn't happy with spaces in pathnames, as in 'C:\Program Files (x86)\Talend-4.2.2\studio\')