What happens when you execute the steps outlined by the IBM Technote 1608271 after you started the DOS Shell (cmd.exe) using the "Run as admin" option ?
Unable to launch TM1 Perspectives: Microsoft Visual Basic Automation Error Unspecified Error
This morning I got the error on my desktop as well after Windows Updates were automatically installed on my computer. Through the advice of our tech guy I followed the instructions for Windows 2007 and Excel 2007 (even though I am running Windows XP and Excel 2003/2007):
Per IBM Tech Note:
Resolving the problem
Unregister and re-register the mscomctl.ocx file.
For 64 bit machines:
regsvr32 /u C:WindowsSysWOW64mscomctl.ocx
regsvr32 C:WindowsSysWOW64mscomctl.ocx
For 32 bit machines:
regsvr32 /u C:WindowsSystem32mscomctl.ocx
regsvr32 C:WindowsSystem32mscomctl.ocx
Following the 32-bit instructions put me back in business.