I have the same model (Medion Titanium MD2900); I also bought it at an ALDI grocery store, and it is my third personal purchase of Medion PCs (more if you count business related, i.e., the times I bought Medion PCs for a company with which I was employed).
I have pushed the unit hard, and have high praise for it. However, I now have two complaints.
1) On the AV buttons on the left side of the kybrd, for controlling volume and CD playback, both during PC activities, and CD-only playback when the unit it off -- the volume buttons keep bugging out; they stop working. I am not really "into" playing CD audio, and I have not tried to use the CD playback controls, but I used the volume controls some, and they kept bugging out. I was able to get them working a time or two by reinstalling the driver, but after a while that got old.
2) Medion's policy on sales of parts is atrocious. From dozens and dozens of other name brands of laptop makers, you can order spare parts and install them. Not with Medion.
Even if all you need to do is replace your keyboard, you must pay to ship your unit to them, pay them for a diagnostic (even if you already know what is wrong), pay for the part, pay them to install the part (even if you already know how to install it), pay for return shipping, and ... do without your laptop in the interim.
For example:
My unit is no longer under warranty. I spilled some water on my keyboard, and it didn't survive it. No surprise. I talk with my hands, and I should have seen the cup on the table. I whacked the cup good, sent it sailing, and water arced through the air and onto the kybrd. After drying out, exactly 6 keys (if I remember right), were non functional. They never returned.

I just plugged in a cheap, full-sized external keyboard (USB), laid it on top of the built in kybrd, and went back to working on the laptop.
Well, at first they were saying: ship, pay for the diag, and pay for the part, pay for the install, ship. They quoted a price on the diag ($95), but not on the part or the install, but they hinted it would be around $300 total. I refused.
Later, I contact them again, and now they are talking $95 for the diag, and $85 for the part, and implying that is all I would pay. Medion wants to force me to pay out near $200 (after shipping & insurance, and probably taxes) I'm sure it will be over $200. That is "robbery."
Dearest Medion:
My unit is not under warranty, so I cannot "void" anything by just installing a kybrd. Just let me order the part, and install it!
BTW: Does anybody out there have a non-functional MD2900, that you are just going to throw out, from which I might convince you to salvage the kybrd (if good), and send it to me? I would pay you for the part and the shipping and handling.
It would help out a small-town pastor who is having to carry a full-sized keyboard around with him, because he is opposed on principle to the company's policy, and who would rather not waste all that money.
