So I was attempting to install Microsoft DPM 2007 on a fresh Windows 2003 R2 X64 Server Machine and everything look like it was working fine until I would get to the actual installation part (after all pre-requisites had been met) and I would prompt me for my Windows install CD and it was trying to find convlog.ex_ and no matter what I did, even pointing it to the convlog.ex_ file it would bomb out with error 810.  What it ended up being was that after the OS install I had added IIS via add/remove programs, windows components and browsed out via a UNC to where I had a Windows 2003 R2 X64 install CD mounted.  So even though IIS installed fine this way, when I ran the DPM install it was looking for the original drive letter that was used for the OS install, in this case Drive Letter D:.  So since I was doing this install remote, I changed my CD drive letter of the physical CD drive from D: to another unused drive letter.  Then using MagicDisc, I mounted an ISO for the Windows 2003 R2 X64 OS CD to Drive letter D:.  I then uninstalled IIS using add/remove programs, once this was uninstalled I re-ran the MS DPM 2007 install this time it automatically installed IIS during the install procedure with out prompting me for my OS install CD.