Forrester’s report, "Lessons Learned From Windows 7 Early Adopters," found generally positive views about Windows 7 among some early adopters. The report considers Windows 7 to be an "evolutionary" advance, rather than a revolutionary change from Windows Vista. “Forrester collected information from nearly 40 customers for the study. IT managers were most excited about not having to rely on third-party software companies for applications such as encryption, WAN management and VPNs. The stumbling block for many organizations migrating to Windows 7 from Windows XP may be application compatibility. Most of the IT managers acquired Windows 7 by buying it preinstalled on new PCs. That approach can avoid potential hardware incompatibility issues. Forrester recommends that IT organizations begin planning for Window 7 deployments in the "late 2010/early 2011 time frame," corresponding to a "major corporate PC refresh cycle." Forrester estimated that about two thirds of XP-based apps can't run natively on Windows 7. One solution to that problem is to adopt client virtualization. One in three IT managers consulted for the report used client virtualization to address such migration issues, and that approach may become part of a future IT trend, according to Forrester's report.