Win7 laptop/print to XP-connected Laserjet 4+

I read the suggestions in the Drivers forum a long time ago and felt technically unable to go ahead with any (instead I added an HP OfficeJet). I wasn't sure if they were talking about just printing to an HP 4+, or if any addressed my problem, or if it mattered.

My HP Laserjet 4+ is connected to my XP desktop computer. I want to be able to also use it to print from my Windows 7 laptop.

One of the suggestions involved using a Sabrent SBT-UPPC (parallel cable?). It didn't explain how to use it (from where to where). There are two cables connected to my LaserJet 4+. One goes to the back of my XP desktop. The other goes to a surge protector. I don't know if it matters, but there's also a Netgear router involved.

I would like now to get the Sabrent cable ($40 in-store at Staples, $10-$12 online at Walmart and BestBuy !?!). From where to where should it be connected?

I went to Staples and was told by the technician that I didn't need a new cable. He said that what stvdot and vent were talking about was simply getting Windows 7 to work with a Laserjet 4+ printer. He said the only way that I could get my Windows 7 laptop to print on the old printer was to 1) connect directly to it, or 2) enable printer sharing.