If that doesn't correct the issue, try this manual method:
1. Browse to C:\WINDOWS\repair
Right-Click and Copy the file named: autoexec.nt *
2. Browse to C:\WINDOWS\System32
Right-Click in that window to Paste the file
(Answer yes if prompted to replace existing file)
* Note: If the file autoexec.nt doesn't exist on your system
right click the link below and select the "Save Target As.."
option to save the file in C:\WINDOWS\System32 http://mvps.org/nibblesnbits/AUTOEXEC.NT