Why am I getting boot errors after a fresh Windows install?

I have a really strange problem. I have a new laptop (no guaranty) and everytime after a clean installation everything is perfectly fine. But when the laptop is powered off for a couple of hours I get this error:

The file may be corrupt. The file header checksum does not match the computed checksum

Also some other errors are thrown like:

\boot\bcd
0xc0000034

It seems that something is corrupted at the moment when the power is off. But how is this possible?

So far I've tried:

• replacing ram (no effect)
• other harddrive (no effect)
• I tried 3 different OS (XP, Vista and windows 7)

It's a Toshiba Satellite A300d notebook.

This error occurs when either of the following conditions is true:

The Windows Boot Manager (Bootmgr) entry is not present in the Boot Configuration Data (BCD) store.

The Boot\BCD file on the active partition is damaged or missing.

http://support.microsoft.com/kb/927391