won't launch. :(

[puffdadder]

hello, sorry to bother you but it seems that i get this error everytime i try and launch KF

Build KillingFloor_Build_[2009-02-09_10.82]

OS: Windows XP 5.1 (Build: 2600)
CPU: AuthenticAMD Unknown processor @ 1996 MHz with 958MB RAM
Video: ATI RADEON XPRESS 200M Series (6543)

Failed to enter Entry: Can't find file 'Entry'

History: UGameEngine::Init <- InitEngine <- FMallocWindows::Free <- FMallocWindows::Free

any known fixes? thanks for your time. this computer can play half life 2, so it should be able to play kf on low settings in my opinion. Great game though (have on my desktop which worx fine) stands up proud against l4d.