I just ran into the same issue with a different OVA.
Windows 7 Pro x64
OVA on local C: drive
vShpere Client installed from VMware-viclient-all-5.0.0-455964.exe
I searched my C: drive (WHERE /R C:\ zlib1.dll) and zlib1.dll is in multiple locations (and aparently different versions, too!), but none are in the PATH (WHERE zlib1.dll). So I copied C:\Program Files (x86)\Common Files\VMware\USB\zlib1.dll to C:\Windows (Win 7 Pro). That seems to have resolved the issue, even if it is not an optimal solution.
I suspect that zlib1.dll may be missing from C:\Program Files (x86)\VMware\Infrastructure\Virtual Infrastructure Client\5.0 or some other VI Client executable directory. This problem may also be related to cases where only the stand alone vSphere Client is installed.
From what I can tell, zlib1.dll is a library routine used for file decompression.
I am open to a better solution....
ASW20ST, thanks for the workaround. Your solution worked for me too. You and I have the exact same setup except the OVA was on my D:\ (Secondary Drive)
Looks like a possible bug somewhere. VMware must be looking for the zlib1.dll in the wrong location.
Installing a zip/unzip package resolved the issue for me. zlib is used in compression utility and the package is looking for that presence.
i installed the freeware (7-zip or winzip) which solves the problem.
Alternatively, you could download the lib from:
and extracts only “zlib1.dll” from there, then copy it to:
C:\Windows\System32\ (for 32-bit windows 7) or
C:\Windows\SysWOW64\ (for 64-bit windows 7)
I know this is an old thread, but I also know how helpful it is for new people to stumble upon old answers with good solutions, so I wanted to add what I know to this thread and hopefully help out any people deploying OVA/OVFs with compressed disks running into non-sensical errors that they are probably googling on.
VMware has confirmed this is a bug with vSphere Client 5, and the workaround is to install zlib1.dll manually "from somewhere else" - we pulled our copy from an earlier install of vSphere Client, I believe. When I asked this question on behalf of SolarWinds, the estimate I got for a built-in fix (update to vSphere Client) was March 2012. In the meantime, copying it manually is the approved workaround.
The two variations on the error I got were:
Unable to access file:
An attempt was made to load a program with an incorrect format.
(Exception from HRESULT: 0x8007000B)
Unable to access file:
Unable to load DLL 'zlib1.dll": The specified module could not be found. (Exception from HRESULT: 0x7007007E)
The workaround is pretty simple:
- Close vSphere Client.
%Program Files%\VMware\Infrastructure\Virtual Infrastructure Client\5.0
- Open vSphere Client and try deploying again.
Attached a copy of a known good zlib1.dll, too.
This problem was pretty frustrating, so hopefully this settles the issue for anyone who got here by error searching
-nicole (SolarWinds PM)
zlib1.dll 67.0 K
thank you, worked for me