Hello,

I generally use Slackware but I have also installed Ubuntu. Because of Ubuntu I have also Grub2 installed.

My problem now is, that I have wireless keyboard and I am not able to select any OS in Grub2.

But my wireless mouse and keyboard have full functionality in the OS itself.

How can I solve this problem?

1: Borrow a keyboard, boot up Slack, reinstall grub to MBR from Slack.
2: Boot Ubuntu Live, get Super Grub disk, burn it, boot Super Grub disk, select GNU Linux, tell it to boot Slack directly, reinstall grub to MBR from Slack. There should be a multitude of ways to get Grub-1.98 into MBR from Ubuntu live session, like using floppy perhaps, boot CD if no floppy, etc.

What has GRUB 2 to do with a wireless keyboard ?
Even tough you use UBuntu it is still possible to make use of GRUB 1
When you're system is booting can you ask fore the BIOS messages ?
If so is the wireless keyboard already there ?

The problem is quite strange.
I can't get into bios but after Grub my keyboard works in all 3 operating systems (windows, slackware and ubuntu).

I have also a second keyboard. I think I'm going to try to install Grub1 through Slackware.

If there is any useful tutorial about it, they are always welcome.

This is a very simple matter.

The OP is using a fancy type of wireless keyboard and mouse that require drivers to work. The operating systems are big and each have hundreds of files so the wireless devices are supported by the drivers inside.

When the boot loader is loaded it has no access to these drivers. A boot loader is very small as either Grub1 or Grub2 can be fitted inside a floppy so it is unrealistic to expect a boot loader can cope with all new devices unassisted by drivers.

The problem is not related to Grub2. It is just Grub2 is in the MBR and the OP got a Grub2 booting screen but a keyboard not responding to the key strokes. So the OP think it might be something to do with Grub2.

The cure is to use a wired standard keyboard.

Well, seeing as you imply the keyboard worked when the grub originated from Slack, theoretically it should still work. I don't know Slack, don't know which version of grub it has, and don't have a fast enough connection to go digging for such info. I'm surprise the poster before me didn't spit it out for you, actually, I know why he/she didn't, but that's irrelevant.
Assuming you only have one drive and nothing out of the ordinary, boot up Slack, open a terminal or console and issue command as sudo or root: grub-install /dev/sda. If you're unsure, just wait a day, if Saikee don't jump on my back, means I gave you the right instructions.
This is assuming Slack uses grub, lilo is the default in some distributions.

Now...
One more thing, I have not had to do this, but it is not uncommon for software to be designed to install the latest version no matter what the dummy at the keyboard wants, hopefully grub is not designed this way and Grub2 stays in the MBR but turns around and looks in Slack's /boot directory for it's configuration, which would leave you bootless, for now.

Slackware and every member of its family including most of the off-shoot from the Slax family use only Lilo as the boot loader.

They account for about 80% of the Lilo market according to my observation.

Lilo is the true Linux Loader and has just about every feature of Grub. Over the years it gradually loses the market to Grub because it needs recompilation every time its boot configuration changed plus it cannot do manual booting. Using a static screen means Lilo cannot display and boot more than 10 systems. Otherwise it is a very respectable and capable boot loader.

Distro like Slackware is one of the oldest and still uses a text installer. It is very configurable and can be made to very run fast. A very solid distro to be appreciated by experienced users.

Today I could solve my problem. Just took out the bios battery for a few minutes.