Is Laserfiche 8.2 client is compatible with Windows 8.1 Enterprise
As has been noted by others it is not officially supported. The only v8 products supported on Windows 8 in the first place are Workflow 8.3.1 and Client/Server 8.3.2. See: https://support.laserfiche.com/KB/1012418. And no v8 products are officially supported on windows 8.1. They might work for you, but they might not and are basically use at your own risk in those environments.
The only release notes that specifically says their version is compatible with Windows version 8.1 is Laserfiche 9.1.
Laserfiche 8.3.2 mentions Windows 8, but version 8.2.1 only mentions Windows 7.
This doesn't mean it won't work. I'm fairly certain it would on a client level.
This link is handy for determining this question: https://support.laserfiche.com/KB/1012113
If you click on the links under the "Service packs and hotfixes" column you'll usually see previous versions and be able to determine this information.
Chris & Firoz,
Some of the non-compatible v8.x releases crash when run on Windows 8. The crashes tend to occur when the client closes and is likely to cause concern with your staff members. I wouldn't install 8.2.x on a Win8.1 system without adequate testing.
However, regardless of functionality, unsupported configurations are exactly that - unsupported, so I think there would need to be a very strong business case for not upgrading to a supported version of Laserfiche.
See this KB Article https://support.laserfiche.com/KB/1012409 for the supported configuration for 8.x
and this one for 9.x: https://support.laserfiche.com/KB/1013137
-Ben