The term "solid piece" is unclear in this context. If you're referring to a single, self-contained installer or a specific type of download, I recommend verifying the integrity of the downloaded file using checksums or digital signatures, if provided by the source.
The software creates dozens of Windows services (e.g., "Siemens OPC Server," "S7DOS Help Service") and hundreds of registry keys. These are essential for OPC enumeration and DCOM configuration. Running from a USB stick, these services would not auto-start. simatic net pc software v15 download portable