lots of questions

1. is enermax a good brand of psu? if not who is?

2. should i sli to get the equivalent of a 7900gs or just get the 7900gs?

3. whats the best brands of motherboards?

4. is cooler master a good brand of cases?

5. do dual cores work on xp?

thanks 

1: Enermax is an excellent brand, easily one of the top 5 power supply brands for home use.

2: A single graphics card is much more stable and worry-free than an SLI setup. As previously stated, it's for enthusiasts or sometimes a cheap upgrade, but not something you want to half-ass right off the bat.

3: DFI, ASUS, and Gigabyte are my top three, although MSI looks to be pushing rather hard to make a name for itself.

4: They're decent enough, for the most part. They're no Lian-Li, but they're not terrible. Depends how much you spend really.

5: Yes they do.