Slow Start-up

My PC has slowed down considerably,it’s stats are
256MB.
Processor x86 Family 15 Model 2 Stepping 4 GenuineIntel ~1991 Mhz
Total Physical Memory 256.00 MB
Available Physical Memory 27.06 MB
Total Virtual Memory 1.13 GB
Available Virtual Memory 704.20 MB
Page File Space 929.83 MB
Windows XP Pro
What should I do?