By data points, do you mean performance counters, passive monitor logs, etc? If so, you can edit the amount of time you keep those in the DB. Configure -> Program Options -> Report Data

If you can't change any of the settings, then the only thing you can do would be to delete the devices and recreate them.

Unfortunately I can't change the amount of time we keep records, and I can't delete the devices and recreate them as that would cause that historical data to be deleted. I'd be accused of tampering with the data just to make it look good. The extra data that I'm talking about is this: SNMP listed physical memory as "Real Memory" in a prior release, and now it thinks that real memory is missing, and lists it as missing memory. For disk utilization, I have missing disks for everytime someone loaded a server onto WUG with the /media/cdrom mounted, as well as every time a virtual disk was cloned, the clone expanded, and the original deleted. For CPUs I have missing CPUs in all virtual servers where they originally had 2 CPUs or 4, but were later downgraded. In each instance it is simply a matter of there being a record of something having been there that doesn't exist any longer. Thank you both for your advice. I guess I'll just have to wait until those data points simply expire.

So those are all performance monitors.  What do you get if you look at the configuration of the performance monitors for one of the devices in question?  You can get there by going into the device's properties, then the performance monitor section and then selecting one and clicking the configure button.

So as an example I'm looking at the disk utilization, which to me is more important than the rest of them. When I click configure, the Configure Disk Utilization menu pops up and says "Collect data for:" and the drop down has selected "All disks", which in the exact instance I'm looking at is a C:\ and E:\ fixed disks. This is a Windows machine, obviously, but used to be Linux, so has data points from an additional 9 disks, things like / and /var and /boot, etc. But the only two showing in this menu are C and E.

Changing the option to "Specific Disks" and selecting the C and E drives should get rid of the old data.