For the benefit of others, had the same problem on a NW 7.4 installation, under Windows Server 2012 R2 and solved the problem as follow:
- While running the sapinst program, when you get the error, go to your SWMP folder, search for vcredist_x64.msi, it will find two files, one under folder VCREDIST2010 and another under folder VCREDIST2005
- Open the folder VCREDIST2010, copy the file and now go to the sapinst_instdir executables (in my case was C:\Program Files\sapinst_instdir\NW740SR1\MSS\INSTALL\STD)
- Paste the file, will ask you to confirm if you want to replace, do so
- Retry the step on sapinst
Weird, but worked great for me, seems that vcredist_x64.msi for 2005 is not compatible with Windows Server 2012 R2....