When upgrading to ITMS 7.5 SP1 you see a message in SIM that an Install readiness check for upgrading to SP1 failed.
Upgrade to SMP 7.5 SP1 is supported from SMP 7.1 SP2 MP1.1 or SMP 7.5 HF6 along with the latest applicable solution specific hot fixes
The Install readiness check checks for different things depending on what you have installed and what you are choosing to install in SIM. If you choose to install a product that is included in ITMS 7.5 SP1 and you have a previous version already install it will check that you are running the latest hotfixes for that product.
The following is what the IRC checks
1. Gets the current ns version and checks if it is less than 7.1.8400. If it is and you select to install SMP 7.5 SP1 then it fails
2. Gets the current ns version and checks if it is equal to 7.1.8400 and if you are installing 7.5 SP1. If true it checks to see MP1.1
product code is found in the registry. If it's not then it fails
3. Gets the current ns version and if it's equal to 7.5.1670 (7.5 shipping) then it will check to see what products you have selected to install.
Depending on the products you have installed and have selected to install it will do the following checks:
A. If you are installing the 7.5 SP1 Platform you need to have the 7.5 HF6 product code in the registry and it must be the correct guid.
B. If you are installing the Deployment solution 7.5 SP1 it's looking for DS75 HF6 product code in the registry and the correct guid
C. If you are installing Inventory Solution 7.5 SP1 it's looking for Inventory Solution HF5 product code in the registry and that it is the correct guid
D. If you are installing Software Management 7.5 SP1 it's looking for Software Management 7.5 HF4 product code is in the registry and if it has the correct guid
E. If you are installing Patch Management 7.5 SP1 it's looking for Patch Management 7.5 HF3 product code to see is it's in the registry. Does not check if guid is correct
F. If you are installing Monitor Pack for Server 7.5 SP1 it's looking for Monitor Pack for Servers 7.5 HF3 product code to is in the registry. Does not check if guid is correct
G. If You are installing CMDB Solution 7.5 SP1 it's checking that CMDB Solution 7.5 HF3 product code is in the registry. Does not check if guid is correct