Strange add-ons in Internet Explorer under 'Microsoft Corporation:

Hello,

 

I recently noticed under show all add-ons on manage add-ons in IE a number of add ons I've never heard of and that are not on other PC's to this one so I'm wondering if anyone may be able to tell me if they're legitimate or not?

 

Add-ons in question are called:

 

In Microsoft Office/Office12

SharePoint Export Database Launcher

SharePoint Stssync Handler

SharePoint OpenDocuments Class

 

In System 32:

OISClientLauncherClass

XML DOM Document 3.0 (there is another labelled just XML DOM Document which is on both)

 

On the other PC these ar not present but two others called:

VIDEO_QUICKTIME Moniker Class

VIDEO_X_MS_WMV Moniker Class

are under system 32.

 

and

 

IETag Factory

in x86/common files/microsoft/shared/Smart Tag.

 

I appreciate these are probably legitimate but I'd like some confirmation either way. Thank you for any assistance anyone can provide on this matter.