ESET Smart Security and ESET NOD32 Antivirus builds 4.0.467 or later are fully compatible with Windows 7 and Windows Server 2008 R2. Previous builds and versions of our software may or may not be compatible with Windows 7 or Windows Server 2008 R2 and are not supported. ESET security products are only supported on full retail versions of Windows 7 and Windows Server 2008 R2. We do not support ESET security products on computers that were upgraded from a Windows 7 or Windows Server 2008 R2 pre-release build (i.e. a Windows Beta or Windows Release Candidate).

If you are running Windows 7 or Windows Server 2008 R2, or are upgrading your previous operating system (O/S) to Windows 7 or Windows Server 2008 R2, please upgrade your ESET security product to the latest 4.0 build (4.0.467 or later). You can download the latest build by clicking here.

NOTE: Windows Server 2008 R2 is a 64-bit O/S only, download the latest build of ESET NOD32 Antivirus 4.0 (64-bit) by clicking here.
 

NOTE: If you are running ESET Smart Security, please enable pre-release updates to receive the latest Windows 7 compatible modules. Follow the steps below to enable pre-release updates:

Enable Pre-Release Updates

1. Open the main program window by clicking the ESET icon next to the system clock or by clicking Start → All Programs → ESET → ESET Smart Security or ESET NOD32 Antivirus.

2. Press the F5 key to open the Advanced Setup window.

3. Click Update in the Advanced Setup tree and then click the Setup... button to enter the Advanced update setup window.

   
   
   Fig. 1-1

4. Select Enable pre-release updates.

   
   
   Fig. 1-2

5. Click OK in the Advanced update setup window to confirm the changes.

Related:

How do I safely upgrade from Windows Vista to Windows 7 with ESET Smart Security installed?