Juts a quick not to all Windows 7 users who face Slow Startup using High Windows Resolution monitor that there is a Hotfix provided by MS itself which solves this issues. This is happening because default dpi display setting is set to a value other than 96 dpi.
To determine whether you must apply this hotfix, check the setting of the Make text or other items larger or smaller option on your computer. To do this, follow these steps:
- Click Start, and then click Control Panel.
- Click Hardware and Sound.
- Click Make text or other items larger or smaller.
If the setting is set to Smaller – 100% (default), you do not have to apply this hotfix.
If the setting is set to a different value, you may have to apply this hotfix.
Get this Hot fix from here and Find more details about it.
Further you can also try using the Startup Manager which lets you control which programs should be enabled or disabled for smoother experience.