The error is like it says on the tin: some software has tried to write to a memory location and has failed.
The standard answer to this problem is that your memory is faulty. Indeed, this can often be the case. And you should try the diagnostic tool Memtest before anything else: click here
Also do a full malware and virus check.
I get this problem myself sometimes and I have run Memtest for hours without a hitch. It is my strong belief that, somehow, a reserved area of memory suddenly becomes, supposedly free. A write operation to this area then results in the message. Note: this is my own wacky idea and I’m sure others may pour scorn upon it!
It happens so infrequently (for me) it is hard to work out what is going on. If you are lucky (???!!) enough for it to happen frequently you may get to the bottom of it by checking what you have running; this will also give clues as to why it is slow to start up. On the startup screen select “Run” and type msconfig into the dialogue box. You can use this to deselect background processes and programs that start without you realising. Having done so, see if startup is quicker, and if the memory problem goes away.
I have a suspicion that virus checkers and Adobe MAY be involved in this mysterious message, but I have no proof! If you have these running in the background, try turning them off, but disconnect from the internet first.