As we've seen in the last few years, every laptop/netbook/tablet manufacturer has created customized power schemes that supposedly deliver better performance, or longer battery life. I've seen bugs in several OEM software packages, but one was recently brought to my attention.
The user saw multiple power schemes by the same name listed in Process Lasso, making a list of about 20 power schemes. I asked the user to check to make sure that Lenovo's software didn't go and actually create 20 power schemes, as I had a hard time envisioning how PL could malfunction in that. It turns out that Lenovo's utility did just that - it created 3 copies of every power scheme!!
From a functional stand-point, it doesn't matter much. Power schemes are identified by a GUID. You can have 100 power schemes all named the same, though the user then couldn't tell them apart.
Let's hope Lenovo has fixed this bug already, or will in the near future. I would auto-clean redundant power schemes from the system, but I would have to analyze the Lenovo software to make sure it was done right. Their software may rely on specific GUIDs of added power schemes, so may rely on the first, or last, of the duplicated sets of entries.