- A screenshot of the error message or pasted text if you receive one.
http://imgur.com/0RVTG
http://imgur.com/6XUTq
- Your system's specifications, CPU, GPU, Operating System (32/64-bit, Service Pack number, Edition, etc), osu! build number, etc.

I'm lazy sooo:

System
--------------------------------------------------------------------------------

Manufacturer Gigabyte Technology Co., Ltd.
Model P55A-UD3
Total amount of system memory 4.00 GB RAM
System type 64-bit operating system
Number of processor cores 4

Storage
--------------------------------------------------------------------------------

Total size of hard disk(s) 931 GB
Disk partition (C:) 292 GB Free (931 GB Total)
Media drive (D:) CD/DVD
Media drive (E:) CD/DVD
Media drive (F:) CD/DVD
Media drive (G:) CD/DVD

Graphics
--------------------------------------------------------------------------------

Display adapter type NVIDIA GeForce GTX 460
Total available graphics memory 2811 MB
Dedicated graphics memory 1024 MB
Dedicated system memory 0 MB
Shared system memory 1787 MB
Display adapter driver version 8.17.12.9610
Primary monitor resolution 1440x900
DirectX version DirectX 10

Edit: Whoops, guess I was too lazy... Windows 7 64x SP1 Enterprise

- What exactly you were doing to obtain this error.

First ever install of osu! A couple of programs in the background, but I doubt they will affect an installation... (such as a game, task manager, foobar 2000 firefox and windows explorer)

- What exactly was caused by the error. What happened?

Tries to install osu!, nope.

- Steps we can take to replicate your error.

Sorry, I have no idea D: If only I could send you my hard drive...

Edit2: I hate jumping the gun, but it seems to be osu! can only work with 32x unless im a stoopid idiot that doesn't know anything...
Edit3: Scratch that, im an stoopid and dont know how to even install osu! on my first try.

Right click and run as admin? And yes 64-bit runs fine with osu!. (And your name's in the second pic if you care to edit it out)

Those pixels under your fav bar remind me of my Aleve/weed days.

When i went to sleep, I was like 'Oh shit! forgot to run as admin, i'll do that tommorrow [Well, on the same day as i like to stay up late]
Tried that just then and, nope. Same error.
No need to edit out my name as that could be fake

Edit: Looking around the forums, osume was suggested to install, so I just tried it and works (it installed nicely). But just to clarify, what are the differences of the two installers (osu!install.exe and osume.exe) ?

Install is just the installer. Osume is the updater. Which will also fix replace corrupted/missing files.

Seems like the updater got me Osu!... But I'm wondering why that error came up as it could impact osu! in the future D: