I have recently set up a new PC with Win7 RC1 loaded. I have also installed the latest version of ESS (4.0.437). It has been running for a couple of weeks now, including being part of a network and there have been no issues at all. ESS is working perfectly on my installation of Win7.
Have the last version of ESS v4 running fine on a Windows 7 RC (32bit) dual core AMD, 2GB ram... No conflicts between windows and Eset.