All the programs I have tested from the Groove library load fine in 64bit DimPro but some programs do not play reliably. I have never used the library for anything other than testing.
There is no need to download the installers again if the hash values are the same as the values posted by Cakewalk.
If you are going to reinstall DimPro and the Expansion Packs, here is a step-by-step approach:
Disable your antivirus software
Uninstall the Expansion Packs
Uninstall DimPro
Delete the two registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Cakewalk Music Software\dp
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Cakewalk Music Software\dp
Run the DimPro installer as administrator
Run the standalone version of DimPro as administrator and register the synth.
Run the Expansion Packs installer as administrator
Enable your antivirus software
Run DimPro and verify expansion pack install, if needed press F5 to refresh the DimPro program browser.