Alright , we have the first prob solved it seems.
Can you follow the instructions below and post the contents of youre MSdos.sys file?
1. Click the Start button, point to Find, then click Files Or Folders.
2. In the Named box, type "msdos.sys" (without quotation marks). In the Look In box, click your boot drive (usually drive C). Click the Find Now button.
3. Use the right mouse button to click the Msdos.sys file and then click Properties on the menu that appears.
4. Click the Read-Only and Hidden check boxes to remove these attributes from the Msdos.sys file and then click OK.
5. Use the right mouse button to click the Msdos.sys file and then click Open With on the menu that appears.
6. In the "Choose the program you want to use" box, click WORDPAD and then click OK.
7. Copy the content to a post here and quit WordPad.
8. Use the right mouse button to click the Msdos.sys file and then click Properties on the menu that appears.
9. Click the Read-Only and Hidden check boxes to set these attributes for the file and then click OK. Close the Find window. 10. Quit and then restart Windows.
Let's see if that helps but i must add that im not really familiar with this problem but maybe someone else has an other idea.