I think I have had this problem before, but w/ fpsc. U know how it said 16bit subsystem up the top, you need to either have a 64mb, 64bit graphics card or an onboard graphice card that is 32mb, 32bit. Signs needs atleast 32bit (32,000 colours) to run. As 16bit hase alot less colours then a 32 bit card... It has new colour handling capabilities when you have it on 32bit.
First when you are on the desktop, right click on you mouse (WHILE DA CURSOR IS ON DA DESKTOP AWAY FROM ANY ICONS).
Secondly, when that drop-down list of options comes down, click on properties, it will be down the very bottom of the drop down list.
Whe the properties window opens up you should see a few other tabs 2 go 2. Up the top, look a round till u c da settings tab. Click on it and down the bottom u will c a rectangular box w/ a drop-down list button on da right. Click on that drop-down list button and you should see a few ##bit settings. Click on the highest number on da left of 'bit'. If your highest bit settings is 16 bit on both pcs, then you would have been lucky to just have a demo, trial of free version... Did this help? If it didn't, could you e-mail me the- version of the product(1,2,3,4/1.1 or somthin'), if there is a virus(using pc-cilin or somthing, if it has 1 email it 2 me), the person/place/date u got it and wether u downloaded it(electronically/for free from www._____.com_____if so). Thanx...