I cant remember the exact make at the moment, but it was relatively cheap. But i did have the same problem when i used the 300W power supply that came with the PC. I think i might replace it too (just in case). I'll let you know if removing the battery makes a difference.
I'm quite experienced with working with capacitors and high voltages, so i wasnt all that worried about the power supply. And like i said, I did check the leads of the power supply with the volt meter and all the connectors are providing the proper voltages. I never thought about the battery...
In my experience, most of my wireless internet problems are caused by external sources such as a cordless phone (many cordless phones run on 2.4ghz, which is the same as wifi), microwave ovens also cause issues. Once i even found out that the huge coil of coaxial cable that i had sitting close...
System Specs:
Processor Brand: AMD Athlon(TM) 64 X2
Processor Speed: 2.4GHz
System Bus: 2000MHz
Cache Memory: 1MB + 1MB on die Level 2
System Memory (RAM): 2GB
Hard Drive Type: Serial ATA (7200 rpm)
Hard Drive Size: 400GB
Graphics: NVIDIA GeForce 6100 and nForce 430 MCP
Modem: 56 Kbps...