unpacking upx packed and scrambled pe

i am facing problem with unpacking upx packed and scrambled pe .Is there any tool available?here is a attachment namely 'remote anything' and is also available at 'www.twd-industries.com/en/downloads.htm'. The problem is of unpacking "slave.exe" when we unpack in winXX then it works fine in win 98/Me but the same unpack exe fail to work in winxp/win200/winnt. when we unpack in winxp/win200/winnt it works ,the same unpack exe fail to work .kindly help. some antivirus can trigger on slave .exe