SAP XI server slows and then dies

Hey guys

My SAP XI server has developed a very strange kind of fault.it works fine for 2-3 days then starts slowing down,i need to refresh it every now and then,and then in a day or two it dies off and wont kick start at all.

I have close to 7GB free in my C drive,have 1GB of RAM and 5GB of virtual memory.

i m installing SAP XI server 3.0

i would really appreciate any help in this regards

Aamir