My MSI U135DX was faster when it was brand new. It is a year and a half old now and runs really slowly. I have defragmented the hard drive and used Ccleaner to fix problems - these caused it to speed up slightly but it is still frustratingly slow. How do I speed it up? Should I overclock the Intel Atom processor? It has 1GB RAM. Should I upgrade it to 2GB? Please advise. Thank you very much.