pc freezes up on start up at times

i turn on pc and it freezes on strat up many times----sometimes will lett me get started browsing then freezes for no reason!! also sometimes get popup saying " virtual memory too low--increasing virtual....." only have one thing running though--thats ususally internet explorrer- -help!!

 

Need some more information than what you have given if you expect some help. Give us the specifications of your computer and OS.