HP PageWide Pro 577 MFP can't scan from any PC, no TWAIN capabilities, but printing works

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HP PageWide Pro 577 MFP prints fine, won't scan from the PCs.

• setup on the network with a reserved IP in DHCP.
• Installed the full software package PW577_DW_Full_WebPack_38.9.1948.exe
• installed on three Windows 7 x64 PCs
• printing works absolutely fine, no issues
• firewall allowances made for various HP apps
  • "C:\Program Files (x86)\HP\HP PageWide Pro 577 MFP\bin\HPScan.exe"

For example, run "C:\Program Files (x86)\HP\HP PageWide Pro 577 MFP\bin\HPScan.exe" and you receive the error message "The HP PageWide Pro 577 MFP was not found." 

There was previously a "HP LaserJet MFP M129-M134" (one of those models) set up on this network and the scanning was working perfectly fine and I'm wondering if that's conflicting with the situation. 

Edit: Moved one of the PCs closer to the printer, hooked up a USB cable, and the scanning is working through USB. However this is unusable for us as we need to scan from multiple PCs and we purchased this printer for this capability. 

Edit #1:  Here is how bad HP technical support is, the support representative asked me, "What is TWAIN? I am not familiar with this application..." I asked him to have someone in second level support call me back. No one called me back. 

Edit #2: Day 2, I called back and asked to escalate it since that didn't happen in the first place, now told by "Sharon" in HP support that the issue which is affecting all 7 computers is due to a "Microsoft Patch, please call MIcrosoft to have them remove this patch." No question asked about the OSs involved, windows build numbers, etc.. She also couldn't tell me what mysterious patch this is, which apparently affects every Windows operating system regardless of patch level. 

It's starting to look like HP isn't supporting TWAIN anymore...