Assuming your PC meets the minimum requirements (and it does), the below refresh/upgrade routine is likely to address most known problems in one shot.
Please do the following steps in the exact order listed:
- Uninstall Spiral Knights (remove game data from steam).
- Install the latest video drivers for your video card (from intel's website, just to be sure).
- Run Windows update and look for graphics driver updates.
- Remove all OLDER VERSIONS of the Java Runtime environment*
- Download the latest Java.
- (Re)install Spiral Knights, then let us know your findings.
*Why should I remove older versions of Java from my system?
(From Oracle on Java.com)
The latest version of Java is always the recommended version as it contains feature updates, vulnerability fixes and performance improvements to previous versions. You can confirm that you have the latest version by visiting the Java Verification page.
Over time, you may have installed multiple versions of Java to run available Java content. In the past, each Java update was installed in separate directories on your system. However, Java updates are now installed in a single directory.
Should I remove older versions of Java?
We highly recommend users remove all older versions of Java from your system.
Keeping old and unsupported versions of Java on your system presents a serious security risk.
Removing older versions of Java from your system ensures that Java applications will run with the most up-to-date security and performance improvements on your system.
How can I remove older versions of Java?
You can safely remove older versions of Java from your system by following the instructions on Java uninstallation instructions for Windows page.
As a last resort, (via the open GL settings in my comment) Disable vertical sync for open GL:
On Microsoft Windows XP:
Access the OpenGL 3D settings here:
Start » Control Panel » Display (or Appearance and Themes » Display) » Settings » Advanced » Intel® Extreme Graphics, Intel® Graphics Media Accelerator Driver, or Intel(R) Graphics and Media Control Panel tab »
Graphics Properties... button » select Advanced Mode (if prompted to select an application mode) » select OpenGL or 3D Settings (or 3D » enable Custom Settings).
To disable vsync on older Intel® graphics products, set Asynchronous Flip to On and click Apply.
With newer Intel graphics products, set Vertical Sync to No and click Apply.