Just to add to our knowledge, which variant of Windows 7 are you using?
I had a similar (though not exactly the same) problem, on Win 7 Home Premium x64 , and have discussed the issues with Joel. It seems to be an issue with the Microsoft runtime files; different programs install (often silently) different variants of the Microsoft runtime, and this seems to be creating issues in Windows 7 (Eraser is not the only application I know to fall foul of it). Perhaps, as time goes on, programmers will learn to recognise and avoid the pitfalls. For the present, the best advice is to try the latest nightly build on the 6.2 fork, from the Eraser downloads page, and see if that works any better for you; it did for me.
Hope this helps,
David