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General question. My company developed a custom software for simulating combat scenarios using the Unreal 3D Engine (2003). It currently runs on XP-based Dell system. Sometime in the Fall Dell is going to stop supplying XP systems. So we need to port it over to a Windows 7 environment.

However, we expect to run into compatibility issues that could be expensive to resolve.

Couple questions:

(1) What kind of issues can we anticipate running the software on a Windows 7 environment?

(2) Are there any solutions to having to fully upgrade the SW to run on Windows 7? For example, is there any way we can run the software on a XP-based virtual OS?

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Doesn't Windows 7 come with a virtual XP? – Jeff Apr 27 '11 at 0:16
Can you fill us in on whether you've done any actual testing, or know of any specific issues that you know will not be compatible? I'm not clear on how you are concluding "we expect to run into compatibility issues that could be expensive to resolve." – Tim Holt Apr 27 '11 at 3:09
We haven't done any testing yet. – keruilin Apr 27 '11 at 19:16
up vote 1 down vote accepted

Microsoft makes a lot of effort to not break compatibility between different versions of their operating systems. Windows 7 is widely available and cheap to purchase, the best thing you can do is buy a copy, install it, then see what if anything is broken, then attempt to fix it. If nothings broken, you've nothing to worry about.

You could always purchase copies of XP and install them onto the new PC's?

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Bad scenario: Use compatibility mode or rebuild Worst comes to worst: Give up and start again – Jonathan Connell Jun 8 '11 at 20:48

UT2003 Engine Compatibility with 32-bit Windows 7:

The first Unreal works in 32-bit Windows 7, (implying, that) you should probably have no problems with the newer UT2003 engine. (Which turns out to basically be the case, please see the end.) So, I went to the trouble, to test the ACTUAL UT2003 engine for you, in 32-bit Windows 7 (Ultimate.)

Testbed (my) hardware: This, (the CPU,) actually turns out to matter, below...

  • Motherboard: Asus M2R32-MVP
  • CPU: AMD Athlon 64 X2 5200+ 2.6GHz Dual-Core
  • Memory: Kingston 4GB DDR2 800 (PC2-6400) CL5
  • Video Card: Sapphire ATI Radeon HD 4850 1GB w/ 11-5_vista32_win7_32_dd_ccc_ocl
  • Hard Drive 1: Mushkin Callisto Deluxe 240GB SATA II MLC SSD
  • Hard Drive 2: Western Digital 500GB 7200RPM 16MB Cache SATA
  • Optical Drive: LG Black 12X BD-R SATA Super Multi WH12LS30

(Windows Updates installed, up to 6/8/2011. As well as various programs.)

Testing and results:

I installed "Unreal Tournament 2003 Retail Version 2107", from three CDs. (On C:\, the SSD.) It won't launch un-patched. (Even before Windows 7. It gives a serious Critical Error.) Then I applied the (last) official "Unreal Tournament 2003 Retail Patch 2225 for Windows". (Epic's 2225 Patch also removes their own SecuROM CD-check, for their Play Disc (Disc 1.)) The game launched flawlessly. I cranked up all of the settings until it said, "HOLY SH*T!" I started "SINGLE PLAYER", watched the intro, beat the first two levels, and entered the third. I quit the game, and then re-launched it, but it wouldn't re-launch! It crashed, saying:

Negative delta time! History: UGameEngine::Tick <- UpdateWorld <- MainLoop

It's a Known Compatibility Issue with AMD X2 Dual-Cores, here are three quickly found fixes:

1) Run UT2003 in Windows 98 / Windows ME Compatibility mode. (Very easy...) (Right-click the 'Play UT2003' icon > Properties > Compatibility, it's there, near the top.)

2) Install "AMD Dual-Core Optimizer Version 1.1.4" from It's basically an updated CPU driver, to compensate for incompatibilities with multi-core CPUs.

3) Use "Win2000 Launcher" from

Oh, and 4) you could also use a single-core CPU. NOT recommended.

I tested 1), and it works. I went to test number 2) for you... I turned off number 1), but, after two (very quick) launches, the launching problem DID NOT return. So I'm unable to test number 2), (without much trouble,) but I'm quite sure it'd also work... Wait... After waiting (I waited about 30 minutes,) the problem DID return, at which time I tested number 2). Number 2) also works, independently of number 1). It will (almost certainly) only work for AMD CPUs. I didn't bother testing number 3). (Or 4).)

Problem, Solved. [Your two questions: (1): Issues are listed here. (2): UT2003 will run anywhere.]

(Also know, versions of Unreal Tournament 2003 purchased from Steam, (by other users,) may not work.)

I then also went "ON-LINE" and played on three different 2225 multi-player servers, without any problems. I went back, used my new ON-LINE account, and watched the single player tutorial which I skipped earlier. I have carefully tested most major functions of the program without experiencing any problems with it.** That's as completely as I can practically test it for you, without having your content. Or getting paid!

Summary and Solution:

So great news, yes, the UT2003 2225 engine works perfectly fine in Windows 7 32-bit! :O) **However, multi-core CPU drivers, may not work well with UT2003! If your CPUs are AMD brand, install the "AMD Dual-Core Optimizer", (OR, you can:) If they're Intel: Run it in Windows 98 / Windows ME Compatibility mode.

If you have any other problems, they would be with the content that you purchased/developed, in which case, see the content creators. And if you can't get their help, there are easily thousands of capable "3D content creators" who would love to help you. (Interview 5 or 10, and surely one (or two) of them will take care of you.) But, you SHOULDN'T have any problems. Definitely not from Windows 7, anyway! Good luck! :O)

Of course, you should test it on a single installation first. Search for Windows 7. ($100.) I just did... (6/8/2011) Microsoft Windows 7 Home Premium SP1 32-bit - OEM $99.99 + Free Shipping ...looks good. (I wouldn't think the difference between Ultimate and Home Premium would matter here.)

P.S. If you're Buying multiple new Computers to run this on, buy just one first, and test it like I did, (if not even more,) first. (If they won't sell or lend you just one, to test with, buy them somewhere else. Really.) P.P.S. (Among other reasons,) to avoid Hardware Compatibility problems, I always strongly recommend avoiding Dell. You said, "However, we expect to run into compatibility issues that could be expensive to resolve." With you using Dell, I totally believe that.

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I don't thinks there should be any issues with it running on Windows 7. I have played every version of Unreal on my Windows 7 desktop.

Windows 7 does require more RAM than Windows XP, so you should take that into account when ordering the computers, as if you have too little ram, the game's performance might not be as high.

I do not know what you have specifically done to the engine in your simulation, but you really just should test this out on Windows 7 machine. You really should be able to find a machine that has Windows 7 on it to test.

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Agreed RE: testing. Has it actually been tested? – Tim Holt Apr 27 '11 at 2:51

Right click the app icon in Windows 7 and bring up the properties. Under the "Compatibility" tab you'll find a checkbox to run the program under compatibility mode for a number of versions of Windows, including XP SP2 and SP3.

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