The Alliance says software piracy is down to 26% in the UK, going by research it had commissioned from analyst IDC.
This figure for 2007 represents a 1% drop from the amount of illegal or unlicensed software used on UK PCs in 2006.
Losses as a result of software piracy hit £925m in the UK, said IDC.
The reduction follows enforcement programmes over the last year in the UK. These included the launch of a dedicated, regional programme, which targeted Glasgow on account of specific piracy problems.
The attention will be turning on Manchester in the coming weeks, said the Alliance.