Model of desktop: Acer Aspire M5640
When I start up the computer, the screen showing the Acer and Intel logo appears for about 30 secs(usually it only appears for about 5 secs). The wireless keyboard and mouse that came with the CPU and moniter do not seem to be working, no matter how many times I press the connect button on them. Therefore pressing f8 or f12 would not be an option.

Then, I will be taken to a screen showing an error message similiar to the following:
WINDOWS FAILED TO START. THIS MAY BE CAUSED BY A RECENT HARDWARE CHANGE. IF POWER WAS INTERRUPTED WHEN WINDOWS WAS SHUTTING DOWN, START WINDOWS NORMALLY.
Below the error message are two options to start srtaup repair or start windows normally.
The default choice is to run the startup repair and after 25 seconds this option is chosen automatically. However, I am brought to a blue screen, showing only a thread of values similiar (I cannoot remember very carefully- the last part is probably correct)to:
STOP:00000A-000000B-0000000C
pls help as I need a solution immediately. tks in advance. PS. as windows vista home premium sp1 32 bit is pre-installed, i don't have the installation CD.