Install Windows 7 Upgrade From Vista With Sound Card Driver Missing?

Working on a client's computer that was blue screening with Vista 32 bit HP desktop gl309aa. She cannot find the original Vista install CD. I determined that the culprit was probably the wifi driver, and hoped to install updated drivers for that, plus video card and sound card drivers. After much fiddling with the system, I finally got it started through Startup Repair long enough to install the video driver. I had to go through 2 sets of memory diagnostics to start it at all, since even safe mode was not working. When I went to do the sound card driver, it required an uninstall first, so I did that, and foolishly went along with the restart to finish the process. Lacking a sound card driver, it blue screened all over again. Tried everything, including many times with HP Recovery, but every time it blue screens before any process can complete. On top of this, while working on it, she had a power "flash" for a second, and now the system is missing BOOTMGR so it won't even try to boot into safe mode or anything else. I have the drivers on flash but cannot install them. I've decided to forget Vista (awful system anyway) and give her Windows 7 instead. Much more stable, and her data is backed up in case she loses it.

am I going to have any problems installing the Windows 7 if the computer still thinks it has no driver for the sound card? And is there a way to install the file before or during the Windows 7 installation so it will go smoothly? Again, BSOD every time I start HP recovery so there is no way to use that, and we will have a new Windows 7 CD to begin this process.