SQL Server 2008 r2 SP1 (Version 10.500.2500.0)

I would like to install cumulative update package 7 on a server with the default instance and one named instance. On installation, the SMS portion is greyed out to default. I can select or unselect the two instances. I had previously tried to install the package on the system but the install created issues on the named instance.

Would not installing the cumulative package on the named instance cause any problems?

Thank you