wp-admin/install.php warning, after i change something !

Dear lady’s and gentleman,

I have a problem that till now, haven’t seen at the forum yet.

Maybe it’s somehting very small and stupid. Still i hope to hear your opinions about this matter.

When i am deleting old messages on my site, rebuild images, or deleting old tages that where showing in my old messages, something very strange is happening after that.
My http://www.myurl.nl/wp-admin/install.php page is suddenly showing up! It’s telliing me welcome to wordpress install page!

Does anyone know why this is happening?

I would welcome every tip or reaction.
I will try everything to solve this problem.

Thank you so much in advance people!

Greet,
P.Stolwijk