Problems after installing

Design time

and then runtime

How to remove these black lines that are visible at runtime?

To reproduce simply put TAdvStringGrid and select Look = glWin7. I'm using C++ Builder XE2. Win7.

This is also present with some other styles as well and effects all existing projects.

I couldn't reproduce this.

Can you verify at runtime with checking grid.Version, that you effectively have linked the app with TAdvStringGrid v7.4.0.0 at runtime?
If not, please search your hard disk for old versions of AdvGrid.pas and cleanup all old version files.

Version I uninstalled previous version before installing this one.

It is tested here with and cannot be reproduced.

Please provide sample source project, exact steps, exact component settings.
Our test: drop component on form, set look=glWin7, run.
It looks identical at runtime as at designtime. 

Like I already described;

1. Create new vcl forms application (or open existing one)
2. Place TAdvStringGrid
3. Set Look property to glWin7
4. Run it.

Video demo: LINK

I do exactly the same thing but I cannot see this issue.

I specified screenshots and even a video demo for you to see the problem, so it's pretty obvious the issue exists. I have projects on hold because of this and expect a bit better answer than "
I do exactly the same thing but I cannot see this issue.".

I installed it on two computers and noticed the same thing. Other styles are messed up as well:

Further more, changing GridLineColor has no effect in runtime:

I can only think you have an incorrect version of ADVGRID.PAS hanging around on your system. Did you scan your FULL hard disk for multiple copies of ADVGRID.PAS and deleted ALL old versions. If a problem persists, please contact us by email with specifics.

Complete 'tmssoftware' folder was deleted upon uninstall. Now uninstalled it again and searched the hard driveand there is no ADVGRID.PAS.

Now installed it again and here it is.
ADVGRID.PAS - SHA1 (C7540304D4B02C5AE57F9001D4D0293A1FCC9CC0)

I asked you to contact us by email.